I am sorry that you’ve had to deal with your father’s behavior and the information on his phone. It makes sense that it is hard for you to have contact with him, when his actions seem so erratic and contradictory.
It is unclear how a social worker got into the family’s orbit, but I would contact the social worker directly and explain that you are scared, uncomfortable, and stressed What you are looking for here is some support outside of your family, and this is the most direct and best way to get it. If this doesn’t work I would bring this to one of your counselors at your high school to express the fact that you have anxiety and a diagnosis of OCD and aren’t feeling supported by your parents. The counselor should be able to give you some support and guidance — or at least direct you toward someone who will be able to hear your concerns and help you deal with your mother and father.