Hi! I'm 20 and I'm just now starting to lose weight after being chunky through high school. I always wanted to do it in high school but I never had enough support. So hopefully you will be different!
I would first consider taking a trip to your doctor and getting off the Lexapro. Unless you really love it, it actually made me gain quite a bit of weight and makes it hard to get it off. I got on Wellbutrin instead, and I love it.
Then I would go to a nutritionist. I went to one for a year and I give her so much credit for helping me tackle my binge eating problem. You'll learn that often times, even though you think you might be eating too much, you are actually malnourished because you're not eating the right things. Focus first on working healthy foods into your diet, get used to cooking them and figure out what you like. Also eating regular, healthy meals is very important. You'll be surprised how much the urge to eat too much unhealthy food in between meals goes away when you're satisfied from good food. Too many people just cut all the bad things out right away instead of easing into it, and then end up having cravings and rebounding.
Next, start exercising and make it MANDATORY. It doesn't matter what you do, you can walk for 20 minutes, but just do it. Exercise is a HUGE deal for everyone, and I have grown to really really like it, it's the highlight of my day. I used to cringe at the thought of running, and now I'm running 2 miles a day and I really enjoy it. I feel icky if I don't.
Above all, though, the most important thing is to have a strong support group. This doesn't mean you have to go make a bunch of friends or tell everyone what you're doing, but it means be committed to writing in a journal about how you're feeling, what you're craving, where you messed up and how you're learning. I also take an hour each day to go on here and hear other people's stories and communicate. People on here are really nice and have some really good advice! Also, since I'm assuming you live with a parent or guardian, it's a good idea to talk with them about it. That was hard for me at family dinners because my mom cooks really delicious but not so healthy foods. Try to make it a family thing, and find some healthy recipes to make for dinner for the family one night, or ask for a favorite healthy food as a side dish. Again, it's all very gradual, and it's a lifestyle change. Nothing happens instantly!
A couple books I recommend:
Overcoming Binge Eating by Christopher Fairburn
The 7 Habits of Highly Effective People by Stephen Covey (not a weight loss book exactly, but this book helps me so much in realizing that anything good in life comes from habits and hard work).
I know it seems like when you look in the mirror that you just want a quick fix, because it sucks being this way. Just try very hard to imagine what it would feel like to be the weight you want to be. Something that helps me sometimes is just pretending I'm skinny. The confidence makes you want to exercise and eat healthy and take care of yourself. The truth is there is no exercise that will magically get rid of your problem areas. But if you want to change, and change for LIFE, there are small things you can do every day that will add up fast. Accept now that this is something that takes time. Set a goal a year from now. If you make mistakes, just keep going! Don't get discouraged. Good luck! Feel free to message me if you need advice.