You're religious, ja? You should pray and think about the good things in life. Focus on those happy things. Focus on the good things about leaving school, getting a new job (being an independent person!), and paying for your own things.
But I also think it is about thinking that you just don't feel young anymore, but dude, you are young if you think 'bout it, yo.
I already know that you storm chase as a cool hobby, but you should set some goals and do some chill activities to get some of that body weight back (and to get some sun, haha). Probably save up some money, join a gym, and consult a physical trainer. They'll (hopefully) do all the number crunching and give you a sense of what your workouts should be like and what you should eat.
Depression isn't a thing to ignore, and it sucks balls. But you must find the source of the problem and meddle with that. Like Bisjac said, it's probably just the stress of gaining more responsibility and moving out of the bird's nest, y'know?