Is ghusl obligatory for someone who wakes up from sleep holding his penis, before anything has been discharged from it, then discharges what is in it after waking up, and only washes his penis?

It is clear that the questioner is afflicted with waswasa (obsessive whispering). Nocturnal emission (ihtilam) is the release of semen during sleep, not while awake. Ghusl (ritual bath) is only obligatory if semen is found upon waking. If semen is released while awake due to lust, ghusl becomes obligatory, whether it is released immediately upon experiencing pleasure or after withholding.