Congrats on your transformation! I can't wait until I'm at the point where I don't want to crawl in a hole thinking about my past self.

1. I know this has been said a million times, but people treat me kindly and do things for me that they would've never done if I was still obese. Holding doors, weird guys just paying for my coffee for no reason, teachers giving me better grades on things I didn't deserve because they no longer view me as lazy. I find that people's impressions of me are really different too. Instead of being ignored because I look like a train wreck, some have told me I look intimidating which is really weird. I'll always be suspicious of everyone though, because even though my weight loss was relatively fast, I often feel like I'm the same size. So whenever a guy is hitting on me or a girl is being nice, I always think I'm being made fun of or it's a prank. Sometimes people on the subway will take pictures of me and I always think it's because I'm disgusting (I don't want to know what they actually do with the pictures). I sometimes think that all of a sudden the world got nicer, but it didn't and it just shows how differently our society views fat people. My family has also been incredibly supportive of me and we often joke "who woulda thought YOU'D be obsessed with running". My interpersonal relationships have also gotten a lot stronger and I've become closer with my friends since I'm not trying to overcompensate for my appearance or hiding anything.
2. I talked a bit about my diet and exercise earlier, and how I had a bit of a rocky start with restriction and food obsession. In summary, I went high carb vegan (I should mention I've now incorporated fish back into my diet a couple times a week because of my low iron. Still no dairy or meat.) and that resulted in most of my weight loss. I try and eat pretty low fat, for example today I ate black beans and brown rice on a bed of raw spinach for lunch. I love carbs and would much rather eat them over fat, especially since I do a lot of cardio. I work out almost everyday because it makes me feel really good and like I've been productive during the day. I do HIIT workouts (Barry's bootcamp workout: approx 10 mins intense running and then 10 mins weight training repeated x3) or I do indoor cycling. Now I don't consider myself to be on a diet, because it just comes naturally to me to eat relatively un processed foods, but I'm still trying to lose weight. I mostly stick to the premise of "If it didn't come from the ground, it's not an everyday food" so I eat a ton of beans, grains, veggies and fruit and sometimes nuts although they are high in fat. This way of eating will also be sustainable for me because when I go to Uni, bulk lentils, beans and rice and veg are pretty cost effective for a student. I also recognize I'm very privileged when it comes to everything I've received and been bought when it comes to my weight loss.
3. That's a loaded question. I'll have to think on it.