You will not make the progress that you wish to make without first dealing with your anxiety, you need to fix the part of you that is broken, or at least start to, only then will you be able to fix the rest of yourself.
Meditate, think consider where your "anxiety" stems from, why do you feel the way you do, what thoughts go through your head and why. People generally dont give a shit about you, i dont mean that in a hurtful way, i mean the entire thought process of them "judging" you or thinking horrible things about you isnt actually happening. Those are your horrible thoughts in your head.
your emotional or comfort eating isnt helping you, look at your relationship with food and try to fix it. Slow down how you eat, chew each mouthfull 20 times (at least) and cut out soft drink, its just liquid calories that you dont need.
Look up a thing called "mindfulness" its basically meditation but its easymode for beginners.
learn some breathing excercises, anxiety, in particular the panic that wells up and makes you leave is a fear response, you can controll that through breathing, slow your shit with long, slow breaths, itll take a while to get it down but trust me it helps a lot.
Walk, go for walks, start with 20 mins then add 10 mins each week. this has multiple positive effects on your body, 1, your doing some excercise which will help you start to lose weight, 2, body chemistry, it releases some endorphins which will help you feel better, 3 it gets you out of the house and off Veeky Forums which will go a long way to getting you out of the toxic mindset you have. Also, it takes you out of your "safe place" and exposes you to the world, getting used to the outside (away from the internet/anime) is going to help eventually build up some self worth and confidence.
Ive been there man, the anxiety, the crippling fear that wells up. You can beat it, but you have to want to, you have to be ready to make the change. Trust me, your life can and will be better.