How does one deal with depression and loneliness?

Last year, on my birthday, my parents had a real big fight. A large one, including hitting and pistols. I haven't been the same since.

This isnt the first time I've been witnessing fights like this since I was a child. But I was always efficient with coping; it didn't bother me as much as it did this time. I've never felt so drained in my 16 years of life. I can't go to school, I can barely gather myself, I can barely study, and I feel lonely most of the time. It's not like the incident haunts me, just caused whatever the ef I'm going through.

I have a few friends, good friends, but they have other, better friends. Not really anyone's priority. And I can't expect them to comfort me.

I just need to pull myself through these next two months. I Have CIE'S in April, and whenever i sit down to study, i cannot study more than half a chapter.

What should i do?