Sorry to hear that Xenon. I wish there was something/anything any of us could say to fix it, but having been medically diagnosed with clinical depression I know that there isn't.
"Overwhelmed" is one of those words that tends to pop up when I have those same sorts of feelings. One suggestion is to not worry about what you're going to do with the rest of your life, worry about what you're going to do with the next month.
In terms of your weight, maybe that just means setting yourself up with an easy opponent to overcome. Instead of trying to eat 1400 calories and go the gym 4 times a week, eat 2000 and go twice (and maybe mix a few walks in). Want a burger? Eat a burger and skip the fries. In other words, improve. All it takes to get from where you are all the way to below 200 pounds is to improve. Even if it's just a little, a small improvement every month or two adds up to big improvements eventually. Think less about what it is you 'should' do, and more about what you know you can do.
As for the relationship, I am so much the wrong person to give advice on that sort of thing.
Chin up, beauty queen. It does get better regardless of what happens.