Of course it is possible that the abuse prevented him from asking him to marry you. From my own experience, I know that the abuse caused my ex to hold back in the relationship. He said he had to refrain from loving me 100% because he needed to protect himself. There were definitely times when we talked about getting married but he was scared. Not only scared of loving me 100%, but also scared of hurting me and scared of what my reaction would be if I really knew him as he sees himself. I do not speculate about these fears - he has told me these things over time. It was that need to protect me (and himself) that eventually caused him to push me away.
It hurts being where you are right now and it's very confusing. What is happening seems illogical. It seems like if you just ask the right question or research more on the internet, things will suddenly make sense and maybe you can fix it. That's not how it works. There is no answer out there that explains it all. Eventually you will get past the need to know "why" because you knowing the "why" isn't going to change the outcome. Only he can do that.
It is hard to accept that space is what he needs right now, but he has to come to a point where he's happy with himself and sees himself as worthy in order to be in a relationship (any relationship) that is going to work.
Take your time and when you are ready, return the focus on healing yourself. Figure out who you are. It's scary but can also be enlightening. Try new things. Meet new people. (To be clear, I'm not talking about dating -- the focus should be on you and not trying to find someone else to distract you from the pain. There's no point in dragging someone else into this situation when you need to be healing). Think about what you enjoy and do that.
"When one door of happiness closes, another opens, but often we look so long at the closed door that we do not see the one that has been opened for us." - H. Keller
"Change & growth take place when a person has risked himself & dares to become involved w/ experimenting w/ his own life." - H. Otto