Nolva will help with gyno since its an antagonist estrogen blocker in breast tissue and I've read some reports a out how it MAY be effective in restoring HPTA. By adding clomid you work the negative feedback loop of the HPTA directly bc clomid acts on hypothalamus estrogen receptors and blocks estrogen from binding there. This prompts natural test production. I've read numerous reports of anecdotal evidence saying 2 serms are always better than one at restoring the natural test production. Actual scientific studies I've yet to see since I don't have access to most of them and don't want to pay to become a member. Clomid has uses as a testosterone producer by getting the HPTA to produce more testosterone and its not suppressive so it may be worth a shot.
Yes it's usually recommended to get bloods done a few weeks after post cycle therapy (pct) to make sure your body's natural production is back online but if you have the spare $50 I'd go to provatemdlabs now and again a few weeks post-PCt just so you have an idea of where your numbers are at now. Next time always get bloods pre and mid cycle so you know your baseline levels since for this cycle we have nothing to compare any future bloodwork to.
There can be a few different causes some of which may be estrogen rebound (did you use Aromatase inhibitor (AI) and which one if so), low test (your post cycle therapy (pct) migh not have worked or its just taking you longer to come back online), a side effect/interaction to nolva or some other medication you could be taking, anxiety about performance causing it (could just be in your head since post cycle therapy (pct) is a fragile time), etc. unfortunately it's very hard to tell since there's no hormonal numbers to work off of. Do you still get erections or is it your desire for sex is not there?