Given what you said stay away from things like 6oxo that have birth defects listed as a possible side effect. For otc supps make sure you read the fine print. I would take zma or at least zinc and magnesium before bedtime. The later is cheaper. Coconut oil before bedtime 1 tbsp.. Overall health plays a role in libido and semen quality. So check diet, exercise, supps and any activity that might defeat your attempts at improving these things. If you can get it clomid might help.
I might be wrong, but your lh and fsh levels are low. You say this bloodwork was before the operation right? I was under the impression that these would both be elevated if you had a bad enough varicocele.
Fsh is responsible for sperm production, which is more important than semen which is like a vessel only. Do you mean improve sperm quality?