Decision: Get back together or break up forever?
Take the pressure off of yourself with the following thought: There is no "wrong" action, just choices and consequences.
If you go back and it turns out to be the wrong thing, you'll know for sure. If you do not go back, you may always wonder if you should have given it one more go, or you may feel peace and relief of not having the anxiety for the same thing to happen again that had happened so many times.
There's a part in each that will be resolved in the outside world, and a part in each that needs to be and can only be resolved within you. If you feel hesitant, it could be intuition or at this point it could be self-protection/fear of not wanting to return to that which you know has the ability to cause you great pain.
Wherever you go, go fully. If you decide to go back, do so with optimism and not with anxiety. If you do not go back, move forward in life with curiosity to the new and not with regrets over the past. There is no wasted time and no wrong choices. Life is just a mix of loving and learning and in either choice,
you will do both.
It would have been a great relationship if he had been more considerate, if he had made you more of a priority, if he'd been much more honest, and if he had been much more kind. But if he'd have been all those things, he'd have been a different person. So accept him as he is and let him go. That will make room in your life for the person who is all those things because he chooses to be, not because you wish he would become them.
Guilt is a powerful motivator. It holds people trapped in places they don't want to be. It will eventually be fulfilled by resentment over a feeling of wasted time. No one really wants to hold you against your will, but they may not realize they're holding on out of fear instead of letting go with love. When you realize you're facing either certain unhappiness or the chance at possible happiness, the decision becomes much more clear. What's best for the long term isn't always what's easiest in the short term. Follow your heart.