I'm going to tell my father I'd only continue seeing him if we saw a therapist/psychiatrist/psychologist
Are you really wanting to do that? Will he respond well to your demands? Was he a bad parent?
Yeah and mom mom agreed to it.
Therapists can help everyone out and make things more civil between the two of you. You are smart to do that before seeing your father again to avoid toxic stress.
This is why people don't like telling their problems.
Don't worry, your secret is safe with me. Do what you like as far as the therapy and things might improve.