Do I Need To Repeat Prayer?
If you know that you’re doing what you’re supposed to but still having habitual doubts, then there’s nothing to worry about. On a related note, think about how you can train yourself in order to omit such doubts. For example, you could try keeping a cheap tally clicker in your pocket and click it once every time you’re about to make ruku.
DISCLAIMER: If anyone that on this thread is stressed out by prayer, I would caution against reading my reply to Mr. Faisal Haroon above (December 14, 2021 at 12:05 pm). Don’t want to cause any further stress.