I have had a BAHA since 2014. I have not experienced any problems with it though so can’t really help you. I did want to reply though and support you.
I wonder if the post is pressing on a nerve by chance or if you had titanium mesh put in with AN surgery if it is touching it perhaps,, not sure this is even a feasible possibility,,,,,, just thinking that since the pain was relieved when post was removed maybe it is something like that,,,,
It’s strange that the area looks good and seems healed yet still hurts so badly,,, I sure hope it resolves soon for you. It would be bad to have to have it removed permanently.