BS1 - ALL OF THE ABOVE, AND MORE!
The deeper you get into any toxic situation, the more traumatic it will be to escape from it.
Get out ASAP and save yourself a whole lot of grief. Just tell your conductors that you're temporarily stopping the study because you have private & personal issues which you have to deal with, and that you'll call them when you've resolved them. If they try to interrogate you, just say, "As I said, the issues are private & personal, but I will contact you when I'm ready."
Then do research and ask questions - here and elsewhere.