Little Voice,
I would not stick by him. Take care of yourself. Easier said than done I know. As long as you struggle on his issues you will only be avoiding your own and hurting yourself.
Being in a relationship with a "sociopath" is like nothing ever experienced before. It's really enough to make you crazy.
Think of it in terms of a non-relationship. It's all one sided. Once they are done with you it's over, at leaste whatever you believed existed.
They are masters of manipulation, lying, and completely self serving.
I struggle accepting this concept.
I too wish there were answers but sometimes it is what it is.
Just my opinion.
Good luck to you.