What is the ruling on the prayers I performed, given that I used to issue fatwas to myself regarding issues of purification related to urinary incontinence, flatulence, and obsessive-compulsive disorder, now that I am aware of my error and have repented?

What you did by issuing a fatwa without knowledge is a grave error, and continuing to pray while you were contaminated with impurity is not permissible, because avoiding impurity is a condition for the validity of prayer according to the majority of scholars. You must make up the prayers you performed while in that state. If you do not know their number, then investigate until you are certain or highly confident that you have fulfilled your obligation. You must also strive to seek knowledge and ask about what is unclear to you.