Same pattern with my husband. He discovered his abuse about 3 years ago, but a lifetime of the exact same behavior. He still finds himself doing this, but is starting to recongnize this pattern and starting to accept compliments and praise from those of us who love him(although it's not always easy for him). Mike 13 good suggestion, my husband has hobbies as well, when he spends time doing this he is more joyful. I have also tried helping him by telling him if a pretty woman smiles at him to accept that and that it's okay to feel attractive, feel good about it. Doesn't mean anything has to happen just means hey someone else thinks I'm attractive, it really helps his self esteem and we are very open in all of our communication-this is a vital part without judgement. We don't always agree but try to see things from the others perspective.
You are not alone. This can be a challenge for many people, I have been through it myself earlier in life.
Your husband will have to see this for what it is and want to change, I wish we could do it for them but we can't, we all have our challenges to overcome.