I dropped FB after being on 'social networking' through Myspace and then FB since about 2005. I found it very difficult to navigate, also found myself being too focused on 'things on FB' or 'how people are on FB' and I think it has given me a very distorted and negative view of humanity. I also find it isn't a particularly safe space for those of us who have some of the 'lower functioning' (I hate functional labels, maybe because I'm 'lower functioning') problems with communication. I found it a very hurtful place, and have also been accused of 'drama' there as you have been accused in this thread. If it's too much for you, drop the website altogether for a break until you feel better.
People unfriend for all sorts of reasons. I have unfriended and blocked there extensively, and have been unfriended. Sometimes it really isn't anything personal at all, sometimes it is. But in the end we are the ones who have to live with ourselves, and we need to do what we feel is best for ourselves. I'm sorry you are hurting.