Is it obligatory for one who suffers from the obsessive thought of madhy (pre-seminal fluid) discharge during prayer to continue praying despite the thought?

The treatment for obsessive thoughts is to ignore them and pay them no mind. If you doubt that pre-seminal fluid (madhiy) has been discharged, do not pay attention to this doubt, and act upon the original principle, which is that nothing has been discharged from you. Strive diligently to turn away from thinking about this matter, and let your attention be directed towards contemplating your prayer, achieving humility, and having presence of heart within it.