This is normal MacDonnell. This is usually what causes the testicular atrophy but it seem's you aren't suffering from this which is a good thing of course.
LH will go low even for primary sufferers on
TRT. This is sometimes referred to as HPTA supression or "shutdown". However complete shutdown is very rare on HRT/
TRT unless you are doing super pyscological dosages of
TRT. What is your regiem like?
Your FSH seem's pretty good which is a plus as this controls alot more than sperm production including seminal fluid production (the amount of jizz!

).
Because you are secondary, your LH/FSH were probably already pretty low before starting
TRT so it shouldn't matter much. HCG will mimic the "LH" signal and in turn stimulate your testicles into producing higher volumes of testosterone and sperm. This will give you the much needed added benefits of
TRT.
TRT + HCG gives most guy's almost 100% normal function. The irony however is that once an artificial LH analogue is introduced your own piturity LH will lower even further and could go off scale even further (again, this is normal).
I believe "normal" LH is around 3.5+ (I am at 3.9 myself) but secondary is usually anything from 2 and below. I drop down to 2.2 while doing
TRT but my total T goes up to 25/6nmol usually.