You feel guilty because he's spent a huge amount of effort making sure you do, to keep you putting up with all this. Whenever you raise something with him about the way he treats you, he acts all hurt and offended and you have to apologise!? That's a way of making sure he never gets criticised or has to own up to how unpleasant he is to you. It's worked, because look, you still feel guilty just for telling us about the truth about what he's like. That's not being mean to him, it's just the facts. Whereas how he has been to you is mean, but he's managed to make you think it's all your fault.
You've been very attached to him because you've been desperate for the affection and attention he can give you and he doles it out in such tiny amounts it always leaves you gasping for more. It's like you being a dog and getting kicked and cursed all day and then being given a scrap of food. You're desperate for the scrap, of course you are. But unlike a dog, once you see this for what it is, you can just walk away, look after yourself, and maybe meet someone nicer. Even if you're single, you will be happier without this.
Don't think of being single as somehow lacking something. By getting rid of this clown, you will be gaining something - more happiness, more stability, and freedom from this miserable cycle of putting up with a load of crap in the hope of a crumb of "niceness".
It's like when I gave up smoking. I read a book that said you're not losing smoking, you're gaining lungfuls of clean air. It really helped!