Is wanting it enough to fix it?

I'm going to try and keep this vague while also giving as much detail as I can, so please bear with me. The person I love is the best I've ever known. We seem to be two halves of the same whole. However, we fight like cats and dogs trying to survive after years of abuse from previous owners. Our relationship started with a spark; it was like one day I just started living in their home. We were inseparable. It's been about 3 years now. We've been broken up for about 3 months... We were constantly fighting. We had one of the most difficult years of out lives. We loved one another but took it out on each other in everyday we could. We both hurt one another deeply. We were evicted from our home during COVID, we lost everything. We tried and tried but couldn't get past our pain. We continued to lash out; bickering, insulting, bullying. We were both guilty. We broke up twice last year. We were torn up over an abortion that we chose to have though we didn't want to but knew it was the right choice. We were angry that our lives seemed to be constantly in turmoil. Both times we managed to work through it but held onto bitterness. Because the third time was the last.... we were both abusive and have been awful in many ways. This last time felt like it was for good. So, at the same time the father of my daughter told me he wanted to get back together. I fell for it. I was desperate for stability. I thought it would be good. We broke up almost 10 years ago after his constant lying and cheating. He didn't change. He is a narcissist who was just preying on my vulnerability. I caught him and immediately left him because I don't love him in that way and felt no desire to stay. I missed my partner. Who loved me no matter my faults. He never cheated or lied we just fought so much and lost sight of what was right in front of us. I feel ashamed for falling into familiarity. For the things I said angry. I've since really taken a hard look at myself and can admit my faults. They have forgiven me and also want us to be able to come back together but feels we are too far gone. There is a lot of detail I don't know how to express right here. But My question is: How can we harmoniously come back together, repair our broken hearts, trust one another, regain our love, forgive what was said and done and not have everyone disappointed in us for being so sickeningly in love or toxic idk..... I want to be with them. I love them. I know we can do it if we try and they love me too. I just am not sure how we can