1.) If you have no sex drive, it could be caused by a number of things, some of which include: Depression, Birth control, or just a loss of interest. Are you getting off before he does, and if not, does he make sure you get off afterwards?
2.) You may be depressed if you are always worrying about people just out to get you. I suggest you go to your doctor and get diagnosed for your issues. Don't feel bad if you are depressed, I was. It was the source to my insecurities, sex drive, and self abuse problems.
3.) There is no reason to wonder if your husband will leave you because of a lack of sex......I mean how long has it really been? If your husband can't look past sex and into what's eating you and why you can't get aroused, then he doesn't deserve to be with you. Relationships are more (or should be) than just sex. If he threatens to leave you for not f***ing, threaten to leave him for not caring.