Is it necessary to purify every place you sit, especially during menstruation, due to your intense obsessive doubts (waswas) that any discharge might contaminate the place?

"Waswas" (obsessive whispering) is an ailment that must be ignored and not given any attention. The body of a menstruating woman and her sweat are pure. Scholars have reached a consensus on the purity of the sweat of a person in a state of major ritual impurity (junub) and a menstruating woman. A menstruating woman is not required to perform ablution (wudu') because she is prohibited from prayer, circumambulation (tawaf (definition)), and touching the Qur'an. The default state for a place and a garment is purity, unless it is confirmed that they have been affected by menstrual traces. You should live your life normally without paying attention to these "waswas."