Telling the Truth?

I ask my husband a lot if he is cheating on me because we have had some marital problems the past few months. Recently he told me that he wouldn’t do that and that he loves me and that I shouldn’t be worried. For some reason, I still get so anxious whenever he goes out of town to work every week. Why do I feel like this?? I don’t want to lose him by bombarding him with questions, but since our marriage is going through a rough patch I feel like it would be easy for him to just cheat on me, especially since he will be hours from home. I hate feeling this way every week... what do I do?