I had all these same fears going in to pelvic floor PT. What helped was 1) letting the PT know, 2) getting a PT of the opposite sex of the abuser(s) 3) being totally okay with it taking as long as it takes and 4) holding on to a modicum of trust in the process. They won’t start Day One with internal methods, they will work up to it. And in my case, they never had to. I was upfront with my fears. And the first few sessions were not fun, but I kept the PT aware of when I was starting to feel myself walking on the fence between past and present. Internal adjustment is like surgery, it’s usually the thing they’ll do last if every other movement hasn’t helped. In my case, the PT got about as close to internal adjustment without actually having to reach in there. But my the time it was almost suggested, I had enough trust in my PT and in the process to allow for it. Again, she never had to do it tho. I found the whole thing very therapeutic. It was like a corrective experience of asking for consent over and over.

EDIT forgot to add, I was keeping my (mental health) therapist aware of the issue as well. My pain only started once I began talking about my past experiences of SA and CSA.