Need sincere Islamic advice. Am I right to let go?

I’m in my early 20s, and for over six years, my heart has been tied to the same man. A long time ago, when we were much younger and more foolish, we had an improper relationship. About six years back, he was unfaithful, and we parted ways. After a few months, though, I reconnected with him. We both felt deep remorse for the haram bond and promised that if there was ever to be a future, we would not speak without need and wait for a proper nikah. So for the last several years, we’ve mostly kept our distance, speaking only a handful of times a year when something serious came up. We tried hard not to slip back into sin. But here’s the heart of the matter: during one of those silent periods, he grew very close to another sister. They talked often, exchanged kind words, and he became emotionally drawn to that friendship. Eventually, she admitted her feelings. He told her he already cared for someone and didn’t start a relationship with her, but he comforted her, telling her she was a good person and that such attachments aren’t easy. Seeing him emotionally intimate with another woman, after everything we’d been through, completely broke whatever fragile trust I had rebuilt. To be just, he has apologized truly and owned his mistakes. From what I’ve seen over the years, he seems to have genuinely changed. I don’t think he’s the same immature person anymore. The problem is… I’m not the same either. For six years, I’ve never really felt safe. No matter how much he tries to calm my heart, I always feel like I could be set aside. Even tiny things can spark the old fear. Peace has left my heart. I still love him, and I know he loves me too. That’s why this choice is so hard. We’re still trying to honor Islamic limits by avoiding idle talk, but I’m starting to wonder if I’m just dragging out what must end. Part of me thinks, if Allah has decreed him for me, it will come about in a halal way no matter what. Another part feels that this attachment itself may be what stops me from healing and finding true tranquility. I’m not writing this to paint him as the bad one. I truly believe he has changed. I’m asking because I can’t tell whether it’s wiser-emotionally and in deen-to keep waiting with my heart still tied, or to close this door for good and entrust the matter to Allah. If you stood where I stand, what would you do? Would you keep hoping that trust can be restored after all these years, or would you let go, even with love still burning inside?