I almost cheated on my girlfriend of two years at the start of my relationship with her and i am being tormented by guilt

for context i adore my girlfriend and would never even dream of being unfaithful to her, but that wasnt always the case and right at the start of the relationship we had pretty significant issues regarding her thinking she was asexual, which was later resolved, but that insecurity led me to have some urges to have intimacy with others, but i always kept it under control and i never cheated, i was disgusted in myself for maybe even wanting to. but one day i caved into these desires and started texting a girl i had previously in a brief situationship with and started flirting with her. things didnt turn sexual despite the fact that i think that was my intention, again this was two years ago so i may have overblown this issue in my head. i blocked her that same day and havent ever spoken to her again or even remotely cheated again, but now time has passed and im filled with this overwhelming sense of guilt over what could have happened. i have extremely strong and frequent urges to tell her but im not sure if id only be doing it to free myself from my guilt at the sake of her happiness in a relationship thats otherwise perfect, what should i do?