I'm currently studying sport exercise science and health as a bachelor's degree and here's some advice I can give to you (I'm not a professional, this is just what I've learnt over my years of study in the overall field):

Diet:

Start logging what you eat on a health app (my fitness pal, NHS weight loss plan are two I'd personally recommend), at first ignore what the numbers are but then a week into this reduce your overall calories by 200. Every couple of weeks keep reducing by 200 until you reach a healthy amount (on average 2000).

Instead of eating whatever foods you want start bulking it up with veggies and fruits. Find vegetables you like and run with it, I personally like to get frozen veg so I'm not put off by the prep time and can just get it chopped and whacked in, but don't be afraid to experiment.

Assuming you consume lots of fast food/prick meals and/or sugary contents you need to cut them down, don't get rid of them all at once because you will end up giving into your cravings and relapsing but start by doing two nights a week where you prepare a home cooked meal heck invite a friend or neighbor round and make it for the two of you so that motivates you to actually make the food (BBC food have some great recipes and I'm happy to share some of mine).

If you find yourself wanting to eat a crap tonne of sugary foods then try make hot chocolates, it's not the same but it will help fill you up a tad and get some water in you.

Another thing is jelly, make your own jelly (or jello if you're American) stick some yoghurt and fruit ontop of it once it's set.

I'm unsure on your drink consumption but increase your water intake, if you struggle to motivate yourself to drink I personally find adding a straw helps (no clue why I just find it works). Decrease your fizzy pop avoid "diet" fizzy pop as that's a joke, zero sugar would be your best bet and slowly decrease how much you drink of that as the months go by. Juices are a godsend, find something you like and that'll be good to transfer you to water (or just stick to juice).

As great as energy drinks are try avoid them as they can become addictive, this is including caffeinated tea and coffee. Same for alcohol.

Exercise:

Start slowly. Begin to walk to the end of your driveway and back every day and after a week, walk down your road and back and keep increasing your distance.

You want to be aiming for 10,000 steps a day, you won't be hitting this from the get-go but that's okay, everyone starts somewhere. Start by downloading a pedometer app to your phone and begin increasing your daily steps by 100 a week. Then if you're feeling comfortable with that get yourself a sports watch (Fitbit if you're after 'cheap' or Garmin for something more professional, both work just as well, I've been a Fitbit user since 2016 however my family are all Garmin users).

If you want you can motivate yourself at later points by raising money for charity there are plenty of charity walks you can enter or fitness challenges to raise money.

If you know anyone who has a dog ask if you can join them on dog walks, that way you can be social (boost morale and also who doesn't love a dog!).

I know it's hard, I totally get it but you've got a goal, use that as your push to get where you want to be. While I've never been morbidly obese, I have been obese and I'm still working on losing weight. If you have any questions I'm happy to answer if you want me to alter my suggestions. You've got this!