I went to Al Rayyah. Didn't have to give any bribe - nor did any people who I know went there - so you're a bit unfortunate. However, I guess your overconfidence out did you in the driving test.

Best idea I can suggest is renting/borrowing a manual car (if they still test on manual) and practicing the specific tests in a car park. I don't understand what exactly you had problems in though.

You would have to find someone to guide you, as I doubt you will get crystal clear instructions on the forum.