((((hugs))))

I'm sorry you are feeling so confused right now. I myself am a first year at university, so trust me when i say i completely understand what you mean, especially by the screaming girls in the hall ... some days i just hide in my room at cry.
As far as the depression goes .. i wouldn't be surprised if you are feeling this way, esp right now. I'm assuming this is a different environment for you, as well as the millions of people that you dont know walking around by you every day. Just that can be enough to make someone upset. Do you have any close friends in your rez that you can talk to or have a good time with? Try and hang in there ... you can do it. I know its hard, and it may seem really lonely at time .. heck even all of the time ... but try and stay close with those that you trust, they are there for you, and it is those relationships that are going to help you through this. Are you far from home?? Try and stay positive doing the things that you enjoy, or even just try and stay busy so that you dont necessarily have as much time to think about things.
I hope that you find what you are looking for, and by the way, welcome to PC! You really have come to a great stop, and there are lots of supportive people here. Feel free to message me whenever if you ever want/need someone to talk to. i feel as though we may be in a similar boat, so i might be able to help.