How do I stop feeling jealous in a relationship after cheating?
I'll give the short answer first and then get into more detail on some things that I think can help get you on the right track. Do you have to ask yourself why you're feeling jealous? Then from there pinpoint the real reason. Address and deal with those reasons to build your self-esteem and confidence.
Possible negative things you could be saying to yourself are, "I am not deserving of actually being loved," "I am such a fool for not seeing that they were cheating on me" and "I am afraid of being alone, and I love them." Once you can digest and understand your feelings, you can start to use some tools that are available to dive in a little deeper. Self-help journals, workbooks, meditation, positive self-talk, and seeking a professional therapist, can all be very beneficial in pointing you in the right direction to boost your self-esteem and self-worth.
Now for my longer answer lol...
A real possible reason you're probably feeling jealous is that deep down inside the cheating validated how you think about yourself. The shame and not feeling enough could be making you feel raw.
Over the years, I have talked to many people, and this question keeps coming up. First off, yes, cheating happens, and it happens often. I am not trying to rain on your parade or be a Debbie Downer, but it's just a thing that comes with the territory in many relationships, unfortunately. A few things have to happen if your relationship is going to have a fighting chance.