Welcome to our forum.
I can see why you would need to take a break, after all the drama. It's not unreasonable to ask J and his girl to give your feelings a chance to settle before they get any further involved. Just, maybe you could give them a timetable or some rough idea of how long to expect? or you could plan to sit down after a month or so and decide where things are.
I think you're just a little rattled right now. You'll probably start to feel better after awhile. Sorry to hear about the cheating; I can see your point about the dishonesty being the worst part.
Glad you could join us.
Love means never having to say, "Put down that meat cleaver!"