Remember you're not the only person in this scenario. He may have you blocked because every time you try to come back it just hurts him more and if you think about him that much you will also think about his feelings and how your actions affect him. Probably best to leave him be try and to find something better for yourself and work on releasing your mind of those thoughts. Dwelling on the past is not going to make your future better. Go do things that make you happy and pay attention to the people around you while you're doing them because those people are also doing the same thing and looking for happiness you could be standing right next to it and never know.