Shannon A had great advice. Therapy can really help, but most of us can't afford it and hey, many therapist aren't really much better than a loving mother who sits down to talk things out and really listen. (I have a friend whose parents sent him to so many different therapists, but few of them ever really helped. I think he's been able to make a lot more progress with friends who take time to listen to him than he ever made with therapists.)
I have an 11-yr-old too and it's so easy just to lecture him instead of asking him questions that might draw him out of his shell. When I actually remember to listen, he often says things that shed light on how he thinks and what he feels. It lets me know how to help him or how to lecture him (grin).
I also wanted to point out that visual impressions are so powerful--especially to young boys since so many of them learn by watching and imitating. Since your son had such a poor example of how to treat women back in March, and since that example was made so much more powerful because it was given by his father, it will be hard to overcome that image that has been imprinted on his brain.
I wanted to suggest that you try to provide your son with excellent examples of how men should treat women. It would probably be most effective if those men were being kind to you. I don't know if there are a few good men in your life who would be willing to come over for dinner or go out to a movie once in a while, etc. for the purpose of being a great role model and doing things like asking how they can help you or offering to help clear the table or do the dishes etc. I know men like that might be hard to find, but maybe some would do it for a good home-cooked meal. Just an idea. I sure wish you the best.
S.