You sound very attached to this relationship still - to what was, and what could have been. I think on some level you do understand that this is in your past, but you keep dragging it into the present because you fear to let it go and move on. Four years is a long time, after all.

If I might suggest a few things you could try, I'd say start with putting your feelings down on paper. All of them, everything. Even if you said it or wrote it before. Do it in one go or add to it when you feel like it, it's your choice. I'd advise against burning it; keep it, don't share it with anyone. Most importantly, do NOT under any circumstances share it with him.

Next - this step is hard but necessary. Stop contacting him. It is essential for you to move out of this very damaging cycle, and I think you too realize that. Block him on Facebook, e-mail etc., delete his number, donate or throw away anything and everything that is his or reminds you of him. Literally purge him from your life, little by little. This might be very difficult to do, but it's the only way you can get on with your life.

Finally - accept that he is now in the past, and give yourself time and space to grieve. Don't keep those feelings bottled down. Cry, scream, punch walls (within reason!), in short express your feelings, accept them, let them pass through you and finally, in time, they will start to peel away and you'll emerge out of this reborn... like a butterfly out of a chrysalis.

I'd also advise you finding someone you can confide in to see you through this difficult time. A friend, relative, online friend - anyone with the openness and kindness to be there for you when you need them.

I hope this all helps. Maybe it's not all what you wanted to hear, but some things are harsh, and some things are hard... that's just the way it is.