so, if he has ED due to low testosterone -- obviously test will help him but, without HCG, it will obviously destroy (make worse) his own testosterone production --- leading to a possible lifetime dependency on testosterone replacement therapy (TRT) (test replacement therapy).
if he has ED problems due to low conversion rate to DHT (possible prostate prob) - DHT (Proviron) will "help" him but might make his original problem worse again by placing a burden on his prostate.
to the original poster - try Human Chorionic Gonadotropin (HCG) first - if it fixes the problem it wasn't your balls - it's your brain (pituitary gland)...
or, at least run some Aromasin by itself for a few weeks -- if it "works" ... well, you won't know "what" was the problem, but you'll, at least, know your balls can produce enough test. If this doesn't work - then??? it still could be your balls, your prostate or your pit gland.
If, BIG "if", you have the need to pee a lot, or have pain right "under" your dick (it would feel like "inside" pain), that's your prostate gland. If it's swollen or blocked or or or ... running test or proviron might hurt your prostate. Go check with your urologist.
At your age you first should know the cause of your ED. And whatever you do run Human Chorionic Gonadotropin (HCG) throughout your cycle (and two weeks thereafter - balls protection) and, maybe finasteride throughout the cycle too (prostate protection).