Is ghusl required upon seeing a clear, water-like fluid or a dry white substance after a wet dream, or upon seeing various fluids after a dream, knowing that these fluids may appear without a wet dream, and how can one distinguish between semen and other fluids given the presence of Waswas (obsessive doubts)?

"Waswasah" (whispering of Satan/obsessive thoughts) is a disease that must be struggled against and ignored. Ghusl (definition) (ritual bathing) is not obligatory unless one is certain of the emission of semen, which necessitates ghusl. If you doubt what has exited, you may choose (between it). There is no way to prevent nocturnal emissions (ihtilam). Ghusl is not required for one who experiences a nocturnal emission unless the emission of semen is confirmed. The issue of whether the Prophet, peace and blessings be upon him, experienced nocturnal emissions is disputed, but the more well-known view is that he did not, because it is from the play of Satan.