bOne,
Sounds like you have 2 different issues the “exploding head” deal may be due to too much pressure against the back side of the head, because you say that the color and temperature aren’t changing to me this means the pressure and circulation are ok. Which leaves the issue of pressure against the glan as the culprit.
So try backing up the hanger a 1/2 inch or so and maybe use a little baby powder to reduce the potential for sliding. It would be nice to get the swim cap material as the first wrap against the skin as well but one thing at a time.
Now the base discomfort sounds like maybe skin stretch, this has created some discomfort for me in the past. The common solution to this is to attach the hanger a little further up on the shaft toward the gland. But since I just suggested moving it back maybe you could tighten the hanger some again to avoid the slipage issue.
Understand hanging isn’t a perfect science yet so a fair amount of trial and error and general fiddling are required in order to get maximum comfort.
Good luck and keep us posted.