Im sorry to hear that you are going through this..I will try to offer my opinion on what you should do...First, the issue of, is your husband doing something or ever did have an affair? If he did, and admitted to it and you two worked things out...this is good..
If he has never had an affair...Do you have any trust issues with him ? And you have to be honest with yourself and ask is it something you feel deep down...regarding your husband ?
If this is not the case, then I would personally start reading from
Psalms in the bible in the evening. And pray before you go to
bed to have your mind clear and peaceful...and to protect you
from enemies of our peaceful sleep...and see how this goes..
Its something that is within you that you have not deal with head-on...let it go....and worrying is also a factor.
Good luck to you..