Are my fasting and prayers valid for the past four days, and does a woman's maniyy (sexual discharge) only exit through intercourse, wet dreams, and masturbation?

Ignoring and turning away from obsessive thoughts and not giving in to them are among the strongest means of overcoming them. Your resistance to obsessive thoughts regarding blood discharge, swallowing it, and your fast being invalidated is correct. Swallowing blood unintentionally does not invalidate the fast, according to the more preponderant opinion. Similarly, resisting obsessive thoughts about the intention to fast is correct, as intention resides in the heart, and whoever intends in his heart to fast, it suffices him. Semen is discharged during intercourse, masturbation, and wet dreams. It may also be discharged sometimes when desire intensifies. If you are uncertain about a discharged fluid, you are not required to perform ghusl unless you are certain that it is semen. Merely thinking about matters of desire during Ramadan daytime does not invalidate the fast. Similarly, the discharge of semen or pre-seminal fluid solely due to thinking does not invalidate the fast according to the majority of scholars. The gaze of a woman at a non-mahram man is a matter of differing opinions; some absolutely prohibit it, while others permit it if there is no fear of desire. However, if accompanied by desire, its prohibition is agreed upon.