No motivation at all

I have been feeling this way for a while now. I think it has to do with depression but i think there's more to it. Although I am enrolled in community college, I have no drive to do well and just think negative thoughts. I used to do well in school when I was a kid but then I got depressed and lost all desire to do well and pretty much lost interest in many things. I see everyone else who is my age going away to college, getting girlfriends, and becoming mature while I stay in the same negative, immature state. I didn't want to go to college and while I always make promises to people I never keep them. I always say I am going to do things, yet hardly ever do them. I am turning into a waste of a person. Please don't say "Snap out of it" or "It gets better, just try" because I have heard those a countless number of times and it doesn't work. I'm not trying to be rude, just letting you know that it's harder than it may sound.

I know its not easy and its not something that someone can just snap out of. You have to figure out what is causing the depression?