It sounds like your younger daughter has similar issues at school as your older one had. Going by multitude of issues you and your family have with your neighbors and your kids school issues I feel like you live in a rough neighborhood where one has to watch their back at all times. School sounds horrid and so is your neighborhood.

Any chance you could look for a better place to live? It’s been long enough that you lived in this nightmarish situation.

If moving is out of the question, look for school of choice for your kid. There has to be something better out there

Also get your kid a therapist ASAP