I'd like to know what the theory is behind this treatment. I don't see why it should be that helpful if you're already producing normal amounts of testosterone. HCG in these amounts almost surely will be suppressive of your other natural hormones, including kisspeptin, GnRH, LH and FSH. It's also likely to create excess estradiol. The main difference between a shutdown caused by hCG and one caused by exogenous testosterone is that the hCG stimulates production of endogenous testosterone. Therefore it's less likely to cause testicular atrophy.
If it were me I would try a trial with a SERM. Then there's no hormonal suppression.
Have you done additional lab testing, including DHT, progesterone, thyroid hormones, DHEA, etc.?
It occurs to me that another difference with hCG use versus testosterone is that at least in young men it can raise progesterone. It would be useful to know levels before and during treatment.