Can i stop it? If so, how?

Okay, I am 17 years old and I am in a 2 year relationship and happier than ever. Nothing is bad between my parents or in my household. But for some reason I am very depressed on and off. But i am also stressed about my future and college and where it will take my relationship. And I over think and over analyze everything. It's a force of habit.. I think this is what is making my depression worse.  How can i stop over thinking and analyzing everything? Please help. I'm lost right now.

[Tryin2BClean]

Wen i was ur age I was the sane.  It might sound trite but wen i laud there at 3am, mind racing, I wld breathe deeply telling myself "out with the bad, in with the good" then I wld tell myself "there's nothing I can do in this moment, its in God's hands"  and I basically "gave it up to God" believe it or not, it worked.  Eventually I got to where it did not happen at all.  Good luck