At numerous times, I knelt in front of the Buddhas to repent and promised to no longer violate the Non-deviant Sex Precept but I would only break my resolve later. I am very ashamed of myself and realize that my offenses are quite serious.
Your predicament is quite commonplace because of the lack of proper training from the religious teachers.
We typically do not give Precepts instructions on the internet but in the interest of helping honest people like yourself, we will tell you how to renounce the Non-deviant Sex Precept.
Just tell anyone who can understand you the following three times:
“I, (say your name), hereby renounce the Non-Deviant Sex Precept of the Buddha’s.”