If unfollowing her on fb helps YOU, do it. You can simply block her and not de-friend her.
It is hard and it is long. But becoming the best you possible is the way to go. You are on that path. I won't repeat what many have already said. You have heard the advice here.
Maybe if you had been able to follow the advice better, you would be in a better place now. But we cope as best we can. You will get there.
Regardless of the spiralling and your attachment,you are still going. Regardless of the reasons you have endured a long struggle for what you believe. I just wanted to drop by and mention that. Well done.
R 25 years M 14 years S11 & S13 Working on it alone since Oct 2014 M in trouble a lot earlier (~2 years) Feb 2016. 1st R chat in a yr. Next R chat Aug'17 Still together