5 year shrinkage not flatline

If you size loss is actually true, especially when your penis is 100% erect, then you should not blame PMO, but have some medical examinations.
Have a complete hormonal check.
Visit a urologist to short out every possible malfunction.
And most important, visit a PT which specialises in pelvic floor rehabilitation. I'm getting constantly better in terms of erection quality/ penis look in flaccid state after i begun the rehab of my pelvic floor.

 

Pmo absolutely will shrink some men’s penis. My husband and I both noticed( about 6-10 yrs married I forget exactly when) but never knew why his shrunk, by a lot. Fast forward 20 years , he gets into recovery and yeah, his d is bigger again, both flaccid and erect.

 

Hey man, maybe you should try reducing your frequency to start off with. If you're O-ing 3-4 times a day, it wont suddenly drop to zero. Your frequency is really high. There was a point of time when I did the same things as you, I definitely did feel much smaller than usual. When I reduced my PMO to like once a day or less, then over time, your size will recover too. Reduce your frequency, start cutting down on P, eventually start to aim for no PMO, and find a real partner. You can do it!