Must I repeat the prayer when a viscous, transparent fluid is discharged before and after urination, and upon finishing or during the Fajr prayer, given the difficulty of purification due to the continuous discharge of drops of urine and fluid?

It seems that the fluid mentioned by the questioner is "wady," and only istinja' (cleansing) and wudu' (ablution) are required for it. If it is found after the prayer at a time when its emission after the prayer is probable, then the prayer does not need to be repeated; rather, one should perform istinja' and wudu'. However, if there is an indication that it was emitted before or during the prayer, then the prayer must be repeated after performing istinja' and wudu'. All of this applies if the emission of the fluid is certain or strongly probable. But if it is merely doubts and whispers (waswasah), then no attention should be paid to them. There should not be excessive exaggeration in istibra' (ensuring no urine remains) so that it does not lead to waswasah. If a person thinks or is certain that the urine has stopped, they should sprinkle their private parts and trousers with water to cut off the waswasah. Istibra' varies from person to person, and the intention is to be reasonably sure that the urinary tract is clear of anything that one fears might be emitted, while avoiding reaching the point of waswasah.