Is it permissible to act upon the fatwa of Ibn Taymiyyah, which allows those suffering from urinary incontinence to perform one ablution (wudu') for each prayer, given the questioner's struggle with obsessive thoughts regarding flatulence, the fact that contracting the anal and bladder muscles causes drops of urine to be released, and the negative impact this has on their psychological state?

The cure for obsessive thoughts (waswas) is to disregard them and pay no attention to them. An oath made under the influence of waswas is not binding, nor is breaking it, because the one suffering from waswas is in a state similar to being compelled. What you mentioned about the frequent discharge of urine is likely due to waswas, and you should not repeat your prayer no matter how much Satan whispers to you. If you are certain, with absolute conviction, that urine is continuously discharging without stopping, then your ruling is that of one afflicted with سلس (urinary incontinence). In this case, perform ablution for each prayer after its time has begun, and pray as much as you wish until that prayer time exits.