Or sometimes, your gut really is correct, and there's something going on.
I'd suggest a good FT (family therapist), Seanna -- one with extensive experience in dealing with infidelity. There are specific things (transparency, etc.) that a formerly-wayward spouse can do to make the betrayed spouse feel more secure in the marriage, and reduce the anxiety. And similarly, as 25 says, the therapist can take steps to make sure you're not "lording it over" your husband for his past infidelity, and they can help you deal with your feelings of paranoia if they feel they are unreasonable.
BOTH parties really need to work hard at recovering from the past infidelity. With a professional who's trained in it, it's extremely hard to successfully navigate those waters.
When you took him back, was there ever a "no-contact" letter sent to his OW? Did your husband agree to a transparency plan with you?
