This is one of those chicken or egg situations. Certainly there are women who use a vibrator to masturbate, get hooked on the strong sensations, and then can’t have an orgasm with only the sensations that a fellow human being can provide. But guilt can also cause someone not to be able to orgasm, and since he is married (and his wife’s illness may be somewhat of an excuse or may make the situation even worse,) it would not be surprising that you would have some feelings of guilt, which could be preventing you from being orgasmic. And this guilt could be subconscious, so you might not know it.

If the problem is caused entirely by your overuse of the vibrator, stop using them and probably after some time has passed, you might be able to have orgasms without them. I can’t tell you to stop seeing this man, especially as I don’t know the entire situation, but you also have to consider that having sex with a married man might not be something that you can do and be sufficiently aroused to have an orgasm. If that’s the case, then perhaps you have to end this relationship.