First of all, well done for writing this. It is another small step away from darkness.
I won't try to lecture you or 'advise' as such. What I would say is that when I was younger, I allowed relationships to entirely dictate my mood and thought that every feeling I had was permanent and that I would never recover. I've never tried to take my own life, but at one stage a long time ago I was so sleep deprived, distressed and lonely that it felt as though life was draining out of me. It was a bad pattern, and eventually it broke, and I started to get better.
Just try to remember that as time passes, part of the human condition allows us to move on - it's the only reason that the death of people we love doesn't drive us all insane. Your feelings are real - grieve the passing of the relationship, allow yourself to feel angry, confused and upset - but in time I hope for you that you can then let them go and you can start the next phase of your life.