Wow, that definitely sounds familiar... I definitely was in that state quite a few times.

What worked/works for me:

I kept in touch with my family and close friends back home. If it wasn't for the old idkfa, I don't know what I would have done in college. I'm pretty sure idkfa kept me from going off the deep end when I was in some really bad periods of time.

I kept as busy as possible. If I always had something to do, somehow it made things better. Things seemed to be worse when I had too much time to think.

I would just prepare for it and expect it at certain times... I knew that I would get homesick for DC for the first day I went home to AK, and I would be homesick for AK for the first two weeks back in DC.