I'm not a doctor so this advice is worth what you paid for it.

If normal feeling returns to your gentleman areas within a short time then don't worry about it. Like someone already said it's just like your foot going to sleep, albeit more concerning when it actually happens. Since you described "normal sexual function" within hours of the class finishing it's clear that everything is still working down there. If things feel significantly less sensitive it might be cause for concern but be aware that the way things feel can often be subjective and it's very easy to convince yourself that you feel a certain way because you're looking out for it.

Try lowering your saddle a little and tilting it so the nose is slightly lower than it currently is (when tilting it you don't want to be lowering the nose by more than about 1/4" at a time) and you'll probably find things get better. If you're sitting on the narrow part of the saddle your man parts will be taking your weight, which isn't supposed to happen. If that happens move your weight backwards, and if that's uncomfortable move your saddle forwards.