Try to have a good talk with your boyfriend and communicate with each other. Don't be suspicious. If you are always thinking alone, even if nothing happens, it will hurt each other's feelings.
If you really have other men pursuing you in your life, then you should sort out your feelings and who you really want, and don't entangle.
Clear your mind. If you can't clean it up, talk to a girlfriend or something, or put it down for a while. Don't think too much. Anxiety can't solve the problem.
Drink half a glass of milk or a small glass of red wine before going to bed, which will make you sleep much better. Or listen to light music before going to bed and relax yourself, so that the quality of sleep will be better and you won't have some messy dreams.