Wow man sorry to hear about that! Don't wish that on anyone. but you kinda answered your own question with the Human Chorionic Gonadotropin (HCG) usage. I can bet your balls were completely inactive my man. You needed a major jump start of Human Chorionic Gonadotropin (HCG) to get em rollin again. Did you ever get bloods drawn mid-cycle, end of cycle and end of pct? well worth the money IMO especially in your situation with all the harsh sides. Without knowing whats going on inside you how do you know how to combat the problem. kinda like throwing darts a a dartboard....accept the dartboard is your health.
Next time I would also add some OTC stuff in PCT like HCGenerate, Unleashed, forma, PhytoSerms and if you want to stay anabolic OastSarms.
So its really not a question of diminishing returns with each cycle, its more a question of how to complete each cycle to its fullest potential.