You’re slender and have a nice, big rod, so I doubt you’re going to hide it, but maybe compression briefs. I always found things like jockstraps to be darn uncomfortable when the random wood came on, though. Rather than trying to hide it, maybe just not accentuating it is a more achievable goal.
Do you have a problem with extra glances and looks to your crotch? I wonder how women deal with extra glances to their breasts. Probably helps determine who is a creep and who they want to interact with further.