If it is really becoming an issue a urologist can resect a portion of the tunica to decrease your girth. I realize this is an extreme option, but if you are still unintentionally gaining girth through spontaneous nocturnal priapism then I don’t know what else you could except try to medicate to diminish your overnight erections. But that might make you lose good sexual function at other times.
There is a case report of a guy who had idiopathic (ie, no medical explanation), spontaneous girth increases to 8.3" mid shaft girth, which obviously interfered with his capacity to have sex with his wife. After lots of workup to exclude all kinds of issues (none of which were present) they found he had a section of thinned tunica that was dilating from normal overnight erections.
The urologists took out a section of his tunica to give him a large normal girth (about 5.5") and he was able to have sex two months later.
Again, not saying you are ready to go down this road, just making you aware in case you decide it is becoming a problem. You’ll likely have to go find a medical center urologist, since this is not an everyday type of surgery. Urologists who do resections for penile cancer would likely be open to doing this kind of thing, but they tend to be high-end specialists and you won’t find them at general urology clinics or community hospitals.
Here’s the case report, in case you’re interested:
https://www.ncb i.nlm.nih.gov/p … les/PMC8847819/