ive done it and fell horribble

i cheated on my girls once and i felt horrible that was with an ex and she finaly forgave me (i think) now ive done it again and fell horrible this was a drunken night with a way older woman JUST DONT DO IT IT ISNT WORTH IT now i want to finish with my partner of 3 years rather than her find out guilt is horrible living with it is hard and cheating is compulsive and cannot be cured