I totally understand what you are going through. Prior to my accident, I was working full time and then going to grad school full time in the evenings. I was also very invovled with coaching high school kids. I was constantly on the go. At 24, I was coming home from work at a merge point completely stopped. Someone hit me doing 45mph and then I hit the car in front of me from the impact. I had two previous concussions in the two years prior from my job. (I worked with students with special needs who could be very aggressive at times).
After my accident, I spent 18 months doing nothing but therapies. I know the depression you feel, as I still deal with it. Last fall, I started back to class part time. However I am still unable to return to work.
I can tell you from what you've told me, you have not given your brain enough time to truly rest. Can you take a medical leave from college? If you want to move forward, you really need to allow your brain to stop and rest. This is the only way you can heal. I took an 18 month medical leave from graduate school and when I started back, it was still only for 2 classes with a great deal of accomodations from my schools disability program.
As for the depression you feel, yes your situation sucks. I can say that, because I've been there
However, if you allow yourself to heal, you can slowly work back to the things you love. Perhaps not hockey, due to the risk of reinjury. But could you coach hockey? Help out the team in another type of way? etc
I would see if there is a sports rehab doctor in your area. They might be able to help you find a cognitive therapist. I found one who has experience with brain injury and she's been really helpful in helping me to accept that this is where my life is right now, but that it won't be this way forever. That has allowed me to permit myself to take it slow, so I can heal and move forward.
This was very hard for me at first as I am very competitive as well, and did not like that I couldn't be my old, fast paced, hard working self. I know how much this hurts and how depressing it is.
But if you allow yourself to focus solely on healing, you can start to feel better physically and emotionally.
My best to you ((hugs))