It sounds like it wouldn't hurt to read some of my motivational hubs. You need to face the music about your incident. Grieving over the death of your friend will take some time, try to remember the good things about your friend
. About your schooling, you need to figure out if the topic of your schooling is something you would be happy doing later in life, does it pay well, is it in high demand? You need to think ahead and plan for the future.
I don't know what your religious beliefs are, but I believe you could get some good support and make some good friends by getting involved in a good church of your choice. Thinking positive and being optimistic and making a plan for yourself and setting goals is the first step in the direction you want your life to go.
Don't be afraid to talk to others about your problems as you are here. If you look long and hard enough you should find the answers you're looking for. You have your whole life ahead of you, don't waste it by making bad decisions. If you do make bad decisions, learn from your mistakes and move on. Good luck, I will keep you in my prayers. I hope this helps.