Sophia, I really feel for you. Someone close to me recently went thru the same thing and it was so painful to see. But, there was nothing I could do to change the other person's heart. I agree with the others, that cutting off contact is the best(even tho it is so so hard). Don't drag out the old pictures and letters. and, yes, you have to block him on facebook

Try to find ways to get your mind off of it. Find FUNNY movies, go to a comedy show, if you believe in God, find comfort in him. Get out into nature and take a walk. Spend time with someone less fortunate than yourself. Just do anything you can to look at the good things in your life that you are grateful for. It will be hard at first but the more you focus on the positive, the easier it will get.

I suffer from long term depression and it comes and goes and when I am in the depths of it, it is something I don't wish on anyone. I can tell you this, things WILL get better for you. No one knows when or how, but someday you will be able to look back on your relationship and you won't have to cry about it.

big hugs to you. I hope you are feeling better soon
Sandy