What should I do to get rid of doubts and waswas (whispers/obsessive thoughts) related to distinguishing between wadi and normal discharge, especially if it appears after urination and is thin, and should I consider the garment impure if I am not sure of the time it appeared?

If you are unsure whether what has come out is wadi or normal moisture, then choose and assign to it the ruling you prefer. If you are unsure about the time it exited, then attribute it to the latest possible time it could have exited. However, if you are unsure whether impurity has stained your garment or not, the default is that it has not stained the garment. Therefore, do not rule that impurity has transferred unless you have absolute certainty, and we warn you against succumbing to waswas (whispers/obsessive thoughts).