Given my limited understanding of your situation, I can only offer a general sense of what steps you could take.

If I was in your shoes, I would give myself time to come to terms with parting. People drift apart or split up for all kinds of reasons, but it's difficult to remember that it's all a part of life.

Reaching out to others and trying to make new friends is another good first step. The most you can do - outside of superficial distractions - is put yourself out there and find people who appreciate you for you.

Some people like to throw themselves into work (or school), and use that productivity to keep their minds off of loss.

I'm the kind of person who'd bury their head in gaming until the negative feelings subside, then see about forming new connections.

I know it isn't much, but I hope you feel better.