Okay, I don't think we've seen a low FSH, high LH man on the forum before, so that's a new one to be honest. Usually they seem coupled together.
But let me point out something. Look at this study:http://www.androscience.com.br/arquivos/arq_67_2005_TEXTO23.pdf
"Semen proﬁle, testicular volume, and hormonal
levels in infertile patients with varicoceles compared
with fertile men with and without varicoceles"
In this study they divided the men up into three groups, including a "healthy group" and two groups with varicocele (fertile and infertile). If you look at this study, all groups tended to have the same LH and FSH levels with one exception: the infertile men with varicocele tended to have elevated FSH, which you don't have of course.
Instead you have elevated LH, so my guess is that this is why your doc is pretty sure that you may be primary. It sounds like you are doing the right thing, though, in taking care of the varicocele in the hopes that this will improve things, but it may not if you have some underlying issue.
Also, in this page on Male Fertility, I mention the study that shows testosterone can improve a little post-varicocele surgery:http://www.peaktestosterone.com/Improving_Fertility
Here are another couple of important points:
--Your testosterone is not just "in the low range". It is low. LabCorp now classifies hypogonadal as anything below 350 ng/dl I believe now. You are very low for your age and, as I document in my book, this puts you at risk for a host of medical issues. PM me and I'll send you my book if you want. So here is the key: are you having classic low testosterone symptoms, such as mental fog/anxiety/depression/E.D/no morning erections? Check this out:http://www.peaktestosterone.com/Testosterone_Levels_Male
--Guess what raises insulin levels and causes blood glucose levels to go haywire generally? Low testosterone. Your doctor should have mentioned this to you. I've got a link on the subject:http://www.peaktestosterone.com/testosterone_diabetes
One last comment: the most important thing is to get the insulin/blood sugar issues under control. If you don't, that will take about 10 years off of your life on average and put you at risk for lots of nasty stuff. The testicles are important. Insulin/blood sugar are just as important. Don't put that on the backburner...