We had a lovely young lady, baptized at around 15 years old, later went to Uni, at around 19 she had a meeting with the Elders and proved to their satisfaction she was pressured in to Baptism,and that she was mentally unstable at the time. She was self harming then.
They accepted her Baptism as invalid, and announced so at the K.H.
She left with a smile on her face, never to be seen at the K.H again, and able to have a normal relationships with her J.W family, including her grand parents. Result !
This was over 20 years ago, I would research thoroughly and see if something along these lines is still possible, and have you anything to lose by trying ? You are simply questioning the validity of your Baptism, not the religion and its teaching, so, build a case, and go for it. Good luck.