Similar patern here - clomid took me from low 300's up to 600+ after being on a few weeks. Mine was self treated, and i didn't test again for about five years, just assumed it would keep working. Various joint problems i was getting last year prompted me to want blood work, and after seeing an advert for Medichecks i got some done - i was lower than before i started, with LH near the top end of range. I have a theory though, that the stress on the gonads from high LH levels from the clomid causes a lot of free radicals inside the testes which reduces testosterone output, in fact i've read studies that say this can happen. I'm currently testing out using various antioxidant combo's while giving the clomid a break. So that might be something you'd to try before giving up on clomid, it probably works best when cycled either way, always using the lowest amount possible ie 12.5mg eod or even twice a week.