What is the ruling regarding the prayers I performed during the period when I thought the prostatic fluid (madhy) had stopped, but it would only stop after six or seven hours, knowing that I practiced masturbation for approximately two years, and am I considered ignorant of ritual impurity (najāsa)?

If you doubt the emission of madhy (pre-seminal fluid) after purification, the default is that your purification and prayer are valid. However, if you are absolutely certain of its emission, then it nullifies ablution and necessitates purifying whatever it touched on the body and clothing. If you do not find enough time for purification during the prayer time, it is sufficient for you to purify yourself after the time begins and pray the obligatory prayer and as many supererogatory prayers as you wish with that purification. Otherwise, you must wait until its emission stops, then perform ablution and pray. If you do not do what is obligatory upon you, then your prayer is invalid and must be repeated due to lacking the condition of purification.