Twenty jelqing strokes with a 2/3 erection, stopping before you reach the glans, is force that would easily be met or exceeded by any number of sexual activities, including ordinary masturbation or intercourse.
That is the part that confuses me. I’m willing to accept some type of injury may have occurred (although some psychological issues may also play a role) but I’ve seen testicles and penises stretched almost to the knees (e.g. infection, injury, etc.) and even after major surgery they often function normally. So willy’s injury (if strictly physical) is confusing me. I have come across posts of guys reporting kinda similar problems and the urologist diagnoses them with performance anxiety, depression, etc. I myself, have had problems (psychological) with getting an erection due to damaging my frenulum due to intercourse when I was younger but it only lasted a few weeks not 15 months or so.