No kids, no marriage? Walk.
You may find as time passes you lose all respect for him. You will see the flaws that allowed him to think it was acceptable to cheat for two years. Low self esteem, dislikes conflict, people pleasing, entitlement, selfishness. That may end up being combined with you just not loving him the same way.
You are not powerful enough to make someone cheat. He cheats because he has a but in his fidelity. I’m faithful but it’s okay if my partner doesn’t know. I’m faithful but it’s okay if I just can’t resist the other person. I’m faithful but I always do the gardening and pay the bills so I’m entitled to get nice feelings from this other person.
Cheats are cheap. School boys in short trousers lying and sneaking about behind the bike sheds with their mates girlfriend. It’s not cool, it’s not sexy or attractive. It’s just a bit grim and sad. I see a cheat on a tv show and look for their poor traits - cheating is abusive - it’s putting their spouse at risk of STDs and PTSD (cheating can cause pisd).
Does he accept he is abusive?
When he touches you do you think ‘you are a cheat?’
I believe some couples can end up with a great marriage. But most cannot. The traits needed to repair a relationship are not the traits a cheat possesses (selflessness, compassion, honesty, okay with confrontation etc).
The best outcome you will have is post traumatic growth that leads to be being a great partner - to another person.