Wow, it really sounds like we are in similar situations. I too think my W has built this huge wall around her heart and she is scared to death to let me back in. Her mom passed away about two weeks before she started A and I think she has real abandonment issues.
The best we can do is just be there sometimes. One important thing that I've learned is to not walk away when we're arguing or otherwise in heavy R talks. It's hard but I find that she really notices. "Don't just do something, stand there."
Keep up the patience KDK, that's the best we can do.