Exhaustion, chest pain, etc. Help?!

I'm 19. Female. Non-smoker. Frequently stressed. Let's see... I know I have insomnia; trouble sleeping, staying asleep, never feeling rested. Lately though I feel like it's been getting worse, I feel dead on my feet during the day. Just completely and totally exhausted all the time. Then there are the chest pains, except I wouldn't really call them pains. Sometimes my chest feels heavy? Like its slowing down and I'm not really breathing? I don't really know how to describe it... I've gotten really dizzy a few times before, but I wasn't sure if it was from that. Anyway, not really sure what the hell is wrong with me and I really, really hate going to the doctors so I tend to avoid it unless it's serious. Oh, and I think I should mention I have some symptoms of depression but I've never gone to a doctor for it, or for anything really.