Hi Shirley,
You said your husband cannot do it anymore. Does he have any medical condition that is causing this lack of interest in sex? Has he seen his doctor lately? If not he needs to go to his doctor so he can treat the underlying causes of his impotence. Has he tried Viagra or Cialis?
Do you still love your husband? If you still do, then you need to be patient with him. If he cannot have sexual intercourse, have you asked him to please you sexually in other ways like oral sex and use of sex toys. I know there is nothing like the real THING but it's better than nothing at all. I would not advise getting it from another man. Cheating him is not a good idea.
If your husband will refuse being seen by the doctor and won't compromise with you and won't give you sexual pleasure, what's the use of being married? Divorce is the final recourse.
Hopefully you both will be able to work this out. After all you probably have been married a long time. Take care and be supportive of him and be patient with his inadequacy. That is what love is all about.