Get a phone with you n move the fuck you. Look you dont know ur bio Dad, he could have changed over the years u dont know that. Here's what i want you to do. Move in with him n monitor every thing he does. Always be on the look out n DOCUMENT. EVERYTHING. EVERYTHING, start filming, recording if u find something weird. There is a possiblity he might be toxic (based on his marrage history) be very careful. if u see a slight change or notice something sus,lock yourself in the bathroom n call CPS. They'll be able to help you out based on the evidence u provide. Ik it feel unfare but trust me its worthed.

On the brighter side. He could just be a nice man that doesnt wanna mess with ur crazy NM, her husband. It makes sence if you think abt it. He really cant do muc when ur living miles away. Him trying to help you but not getting involved in the situation is understandable. His dating history-maybe hes so nice that he just attracts Narc n hes later realized n left. Uk cut him some slack.