You might just be depressed, like it's been said above, because your boyfriend went away.
That is very depressing.
But maybe they call that, situational. Like, you do poorly on a test, and you feel bad about that.
Like, my psychiatrist, who treats me for bi-polar, like I get manic and I get depressed with my medicines.
So, then my wife passed away from a long illness almost 8 years now, and the first few years were kinda tough, and my psychiatrist was saying something like,. get over it.
What helped me the most was, I would have like a health care worker come in a day or two a week. And in talking to them, and them taking me places, I would start having a life on my own, rather than the life I used to have with my wife.
And in so doing, my psychic did not so much long for the past, as it looked forward to the future. So, in getting out, going to school, volunteering, whatever, you meet other people and situations, and they can take your mind off of the past.
People, activities, projects, it's what helped me, anyway. And wasn't my psychiatrist glad.
Since you go to school, don't you see a lot of people everyday, and there's a lot to do. You're in a good situation to do that, being around people all day.
Do you have a fellow student you can confide in? Tell that person your troubles?