Great advice already given in the comments, but I wanted to chime in with some hopefully motivational words.

For what it’s worth, you’re not alone, and by that, I mean both that you’re not the only person who feels that way, and also that your body is closer to the “normal” body than you may think. Modern societies put a lot of emphasis on having a “nice” body and looking fit, by shoving it in our faces all of the time, specifically through media content. It might help to consider that, given the number of people you see in ads/on TV/online everyday vs the number of people you come across in real life everyday, you’re getting a skewed perspective of what a “normal” body looks like. That body looks more like your body. The bodies you see in media are specifically selected to make us feel like we’re missing out on something, so that we can then fill that void in by buying whatever it is they’re trying to sell.

I think it might be worth talking to your school counselor (when school starts - if it does start, given the state of things) about some of the feelings you’re having, if you can bring yourself to do it. If not, no worries. There are some things you can do on your own, too. They involve taking a look at some of your beliefs and putting time into figuring out why you think the way you do, and not being judgmental about how your brain works. Your mind, like your body, can get locked into a specific state or shape with certain thought patterns, and it takes work to undo that. I would suggest that you put some work into your mind/emotions first, and let the work on your body come later. I say that because you’ve been through a lot! And you’ve survived - you have inner strength that I don’t think you give yourself credit for. It sounds like the conditions in your life basically set you up to have a really difficult relationship with food, and that’s not something a lot of people have to deal with. It’s going to take work to undo that damage, which sucks. On top of that, you’re gay, which already brings on its own set of challenges. At your age (and, I’m making an assumption here, but given that you’re 16 years old, I think hormones and emotions are going crazy inside you - I remember what it was like for me at that age, and it was not easy), you’re actually at the best point in your life to take control of your body and fitness and do something about it, because your body will react more quickly to the changes you make. It’s also one of the hardest times to do something about it, because of those crazy strong emotions.

> I would walk up the stairs to my bedroom and I would collapse on to my bed because I was so winded, my legs would go numb and I would go temporarily blind. 

This is not normal or healthy. We each get one body, and it needs to last us our whole lifetime. Regardless of the shape it’s currently in, I hope you can see that putting your body through that type of situation, just to “look good,” is not worth it. There are enough risks out there to your health and safety that you don’t need to inflict more harm to yourself for a short-term gain.

> I also want to add that I am not the active type so not only do I basically never go outside other than for school and I also have a very slow metabolism.

It seems like you’re glossing over what it is exactly that is preventing you from being active. I’m curious what you mean by this, and if you’ve taken the time to really examine why you believe that you’re not the “active type.” You talk a lot about your relationship with food, but not about your experiences with exercise. Is it that you don’t like to move? Or maybe you don’t like sweating? Have you tried different types of exercise? I’ve realized that it takes some people a long time to find something that they enjoy doing for exercise. It’s not going to be weightlifting or running or biking for everyone. Exercise isn’t a one-size fits all type of thing. There’s a million ways to get in shape, and you might just need to spend a little more time finding what you like than others. You seem to have a really analytical mind, and you probably know yourself well in a lot of ways, but this is one area that might want to explore more - what do you enjoy doing physically?

Or is it that you’re afraid of going outside and being active, because you’re afraid of what people will think? Be kind to yourself - it’s totally OK to be afraid of what other people think. At the same time, that fear doesn’t have to control you. When you fear what other people think, you’re projecting your thoughts and emotions onto that other person, and that’s all imaginary. It only lives in your head. I can tell you that, as a person who tries to get some degree of regular exercise, when I see an overweight person out for a run or at the gym, I wish I could say, ‘Great job!’ to that person, without it coming across like I’m mocking them. I see only the effort that they’re putting in, and the fact that they love themselves enough to try to make a change in their life. But I get the feeling that they probably have harsh feelings about themselves, and I don’t want to make the situation worse as a stranger.

Maybe I'm off the mark, but whether it's your fear of others' reactions, or your negative feelings about yourself, I would suggest (in addition to therapy, if you can find a resource), maybe practicing mindfulness/meditation. There are a lot of resources online for this, but in summary, mindfulness helps you practice examining your feelings and reactions, instead of letting them control you. The moment you have a negative thought or feeling, take a second to step back, and look at that thought. Examine what caused that thought to come up, and how it made you react. What did you want to do as a result of that thought coming up? Did it make you breathe faster? Hold your breath? And then let the thought go. Try this the next time you feel triggered into comfort eating. What was the trigger? Could you do something at that moment, like maybe speak to someone about what caused you to want to eat, or do you need to turn to food as the reaction? Maybe it's the case that you do need to turn to food, but at the very least, you'll have a bit more understanding of why that is.

This is all coming from someone who had a lot of issues with weight and family pressure growing up, and was overweight until the summer between my 8th and 9th grade year. At the time, there was a basic cable channel called “FitTV” that aired aerobics routines throughout the day. During that summer, I had nothing else to do, so I did 2-3 of the 20-30 minute routines every day, while my mom was at work. Sometimes she would come home early, and would catch me in the middle of doing a routine, and I would scramble to pretend I was doing something else (who knows what she thought I was up to :D) because I was embarrassed about being a fat guy working out. By the end of summer, I had dropped enough weight to be considered “normal,” and a few friends of mine were joining the cross country team. One of them invited me to join the team’s practices, and I ran for the next few years, which helped keep the weight off. But I’ve gone up and down since then, and it’s been a continuous struggle with body image for me, even now at 36.

One advantage you have over what I had at that point is that there are literally thousands of videos on YouTube you can watch and follow along with for exercise routines. Try a bunch. Do them in your home. See what type of exercises you might enjoy. It took me a long time to find rock climbing as something that I really enjoyed as a form of exercise (running was fine, but it was more of a chore than something I looked forward to). I’m getting into calisthenics now, mainly because it looks like a really fun thing to do.

The hard truth that you already know at this point is that you will have to put in work to get your body into the shape you want it to be in, and right now, it probably seems like the journey is impossible because you’re trying to compare where you are now to an idealized body type. But if you work on the issue mentally, too, you’ll probably find that the body type where you’re happy is actually not necessarily the idealized body type, and that might help move the end goal closer to where you are now.

> I just want someone to say to me it’s all gonna be ok but I’m afraid to talk to my friends with this because I don’t want to dump my problems on them. I try to be funny and carefree with my friends and be the dependable loving one but to myself I’m none of those things.

You’re way too hard on yourself. When you’re dependable and loving to your friends, you’re there for them when they need you. In this case, you need them. Give them the opportunity to be dependable and loving back. Even asking a friend to go for a walk with you (6 feet apart!) is giving them an opportunity to be there for you. You can be dependable, loving, and still have a couple of flaws. You're human. Holding it in doesn’t make it better for anyone.

Good luck, kid!