Thank you for contacting JustAnswer.
I am sorry to hear about the problems you are experiencing. The first step to consider here is that you have a right to your feelings, whatever they are. Allowing yourself to feel your feelings without judging them will allow you to work through them much more quickly. You may start by writing him a letter (that you don't send) where you can write whatever you are feeling and be as angry and jealous as you want - and then shred it, do not send it to him or leave it laying around. The next step is to consider whether he has a pattern of acting in a way that is trustworthy or untrustworthy. Keep in mind that, in general, past behavior predicts future behavior, so his past actions should help you to determine whether you can trust him here. Additionally, it is important to talk about this in a calm way as high emotions will take this into an irrational conversation. A heart to heart talk about this concern could be very helpful. Jealousy often comes up when we are not feeling confident in ourselves. Is this perhaps a reminder to work on improving your self esteem and take good care of yourself through exercise, eating right, and getting support from friends and family. The more you recognize that you are worth wanting to be in a relationship with the less you might jump to conclusions that someone is looking elsewhere. Of course if you feel that you have evidence that he is being untrustworthy, then you need to remind yourself that you deserve someone who wants to be in a relationship with you. I hope this answer is helpful. Please let me know if I can clarify further.