You discovered that you are still a sexual being with needs and desires. Good for you! There is no reason why it should not be that way. If your husband does not want to play any more, he can see his doctor to see if he can get some help.
There is nothing wrong with being sexual. It might have surprised you, but it is not unnatural at all. During and after menopause, orgasms will do wonders for your sexual and genital health, and it is doctor approved and encouraged.
As long as you do not deny your husband sex when he wants to participate, there is nothing to feel guilty about helping yourself, or fantasizing. The best option will however be to make him a part of it.