Advice please ?

Ok so I have a boyfriend and we argue and fight a lot and 2 years ago we actually broke up because of it and I had a relationship with another person for a time wasn’t serious and didn’t get together. And it causes conflict between me and my partner because he stayed single for the time we split and I never in a way I feel awful for saying this but I can’t help but miss the person because he was always there for me. Me and my boyfriend don’t see eye to eye most of the time and argue a lot and he will accuse me of cheating with this said person and I would never cheat but I just feel guilty because I really do miss him being there I just feel as though there’s something missing in the relationship. I know I’ll get slammed for this because I look like a slut or whatever I just would love some advice because I’m eating myself up for it.
Advice please ?
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