Facing and uphill battle

I’m in love with a wonderful woman, however I had so many walls up in the beginning that it kept me from letting her in emotionally for too long. She lost hope that I would let her in and tried to walk away. We keep coming back to each other but she is now in a on and off toxic relationship and can’t see how toxic it is. On top of that she has started to build walls towards me. I know she loves me and I know given the chance I can win her love back. But her old wounds and now this toxic relationship she is going back and forth on is creating an uphill battle. Not just for me but for her too. I’m trying to be emotionally mature enough to say if we aren’t meant to be then ok, even though I 100% believe she is the one, but I know this guy she is trying to hang onto is toxic as the day is long. From name calling to gas lighting and much worse behavior. Every journal article I’ve read screams toxic. But she can’t see it. Or she doesn’t want to see it for a variety or reasons. I don’t know. All I know is every time he hurts her my heart shatters. I can’t stand to see her in pain. I don’t know what to do.