How long can you carry the guilt? Demons in my head....

This is probably the most difficult post I have ever written.
Four out of four. As indicated in my last post, my eldest daughter has come clean with her particular mental health issues 😔. Although not the same content, they do have one direct connection 😔😔😔 and this is where the difficulty starts. The connection, is my late husband.
You see he was a very strict parent. In fact beyond strict.
She was, I feel victimised, if she didn't do exactly as she was told. I'm not saying he hit her, but he was very controlling, and very quick tempered, with a viscous tongue. What makes it worse is, I did nothing to stop it. At times, I also took part in this.
As she got older, I did feel guilty about this. By this time, I had two more kids. This relationship was mostly toxic, and yet I didn't leave. I thought about it, lots of times, but I didn't leave. She had a very tough time growing up, and I stood by, and let it happen...
I stupidly thought, that after my husband died, I would have time to "make it up" to my daughter. Incredibly stupidly.
She's a grown woman now, and all this treatment she endured is starting to haunt her. Mostly now, why I behaved like I did.
Tomorrow, we plan to discuss all this. I'm not looking forward to it, and will not make excuses for my behaviour. It would be easy to blame the dead guy, but let's face it, I'm guilty as charged. I failed her, and nothing can fix that. 😔😔😔