Is it necessary to wash clothes, bed sheets, and everything suspected of being stained with madhiy (pre-seminal fluid), after the questioner has been afflicted with obsessive-compulsive disorder?

Al-madhiy (pre-seminal fluid) is impure (najis) and invalidates wudu. It is obligatory to wash whatever parts of the body and clothing you are certain the madhiy has reached. Its purification is achieved by drenching it with water. As for what you doubt has been afflicted by madhiy, you are not obligated to wash it; rather, it is pure until you are certain of its impurity. It is advisable to disregard ritual purity obsessions and not pay attention to them.