i know im being paranoid

I think it's just guilt

Cities are big places, what chance is there really that he would find you? Think about it logically, he would literally have to go through every single person in the city to find you.
Take a few deep breaths and try to stop thinking about him. If this is how he makes you feel you should probably stop talking to him permanently.

*VioletRaven*

I know how hard it is when one thought starts to dominate it seems like you can't do anything else. What I try to do is let as much of the anxiety out on paper or in type as I can then throw myself into doing something that will take up all my concentration, like making an intricate piece of jewelley or doing some kind of craft you enjoy?
You could try doing something mindless like writting christmas cards to everyone you know, it is so monotonous you just stop thinking, though the risk is that your mind wanders back to the problem.
*VioletRaven*

There is nothing abnormal about it, though to tell you the truth I have a couple of problems and I think they contribute to me blowing things out of proportion, but this may not be the case for you.
It IS normal to worry about things sometims but if you feel that it is getting out of hand I suggest going to see a proffessional, because once you know what causes these irrational thoughts it is easier to find way to improve the situation.

Yeah, I can see from what you have said that you do care about your husband, and this fear of him finding out proves that you don't want to loose him.

I know it may seem hard but I think comming clean may be the way to rid yourself of this. It is your decision, no one can tell you what to do but this is my best advice. If you can't tell him, maybe write a letter as though you were, and keep it. It may be what you need to rid yourself of the guilt.