Hi JJJJJJJ,
We all want to be the best parents we can be and none of us is perfect.
I was married 20 years to an alcoholic and my SO (significant other) was married to his uBPDxw (undiagnosed BPD ex-wife) for 17. All of our children have felt the effects of our dysfunctional marriages. We were not perfect, we stayed for various reasons, and we were co-dependent. We were not perfect but thank goodness our kids had us to give some normalcy, some stability, give them love, and to meet more of their needs than would have been met had we been absent. I would like to add that since we left those relationships our children are thriving... .It isn't always perfect, it isn't always wonderful, the kids have some "fleas" (learned behaviors from the dysfunctional parent) but they are happy, working, going to school, hanging out with friends etc... .IMO much of the damage can be undone, with support, therapy and healthy examples... .kids are resilient.
I would stop focusing on what you did or didn't do in the past (other than what you can learn from those experiences)... .what's done is done.
Focus on now and the future. Show your daughter what a good example you can be now and going forward. You might feel guilty, but you are by no means helpless. You are doing something right the improved relationship with your daughter should tell you that, you have got her going to therapy, and you obviously care deeply for her, these are all positive things. (I got all of those goods things just from your short post

)
I also want to say own what is yours to own, but don't take the blame that should lie elsewhere... .Don't beat yourself up. (You might consider therapy for yourself too if the guilt is too overwhelming )
I'm glad you posted and have joined the group. Please keep reaching out the members here are great at giving ideas, support and a listening ear.
Take Care,
Panda39