I don't know how things go in the USA but in my country if anyone was to threaten to kill me, like a real threat not some shit talk, I would call the police and they would deal with that. Even more so if I told them I have a disability of some sort and can't defend myself.
Also, you need to contact a social assistance office, or whatever you may have like that in your town/region/state, because you need to get away from them and be able to sustain yourself. A change that will most certainly take a lot of your energy and focus — one more reason to let the police deal with the death threat.
Real Marseille soap (savon de Marseille, as we say here in France) is a great 100% natural soap that is not agressive to the skin. But beware if you try to buy some, as there is a vast majority of cheap knock-off edit: that aren't Marseille soap at all.