It was painful to read your letter because there was nothing in it about you being loved in this relationship. Reread it. All along the way you have been overriding your better judgment. The more you try to make him feel better — the more he escalated. I would use the current separation as your springboard out of the relationship. This isn’t a good connection and it has gotten worse. Your boyfriend isn’t looking to change at all. He is only justifying his anger and frustrations.
This is a lopsided relationship. There isn’t much of anything here for you. I would work on protecting yourself from his verbal and emotional abuse by staying away and getting on with your life. It is not your job to fix him, help him, or support him anymore.
Use this relationship as a guideline of what you don’t want in the next.