I am so sorry to hear of this very scary incident. I can imagine how awful it must have felt. And rearing is something that is really serious. I know it scares me for sure.
I am going to say that you and your horse need more work on getting her more attuned to the idea that when she is frightened she must go forward. It was right of you to try to move her feet, anywhere, but something in her feels that she cannot move foreward and she must go up.
I am not a trainer, but I remember watching my teacher work with a horse that when scared would kind of freeze, until he could freeze no more. Then he would fall apart. She wanted him to not freeze at all. She wanted him to react while his fear was smaller. So, she held him on a line about 6 feet long and kept moving the scary thing (in this case I think it was fly spray) on to him and actually asking him to move at the same time. He would freeze, then explode, but since she had the line, he could only go forward around her. At first she stopped spraying she he went forward with the fear instead of trying to bolt away. Eventually, she continued spraying him gently but allowed him to move forward (around her) until he decided he could stop AND tolerate the spray.
You might be able to do something like this with a tarp or some other scary thing. I guess it's kind of "sacking out" but the object is not that the horse just stands there and flinches, but that it walks forward until it really is relaxed and doesn't care about the object . NOT just standing there, frozen , gritting it's teeth until it can't stand it and must go out or up.
Again, I am not a trainer so this is just something I observed. You can make of it what you will.
I hope you can find a safe way to progress through this.
And hope you feel better soon.