Have you tried using toys?
Personally, I'm damn near impossible to finish off from sex alone, and the toys really help.
Sometimes it's a matter of association as well. If you largely associate your boyfriend with pleasure you're going to get turned on by him and it sounds like you don't associate your husband with pleasure anymore.
Using toys and such to stimulate yourself during sex, may still not directly be him turning you on but it really helps in associating your lover with the pleasure your receiving.
Mutual masturbation can work in quite the same way. I think, you just need to experience pleasure around your husband again and then when you're with him, in a similar setting, your memories and physical associations should do the rest for you.