AITA for cheating one time when my ex cheated on me for multiple months?

so this happened a year ago and i think that this night was fair and pay back for dragging me along for months around 4-3 for context my ex had been cheating on me with her best friend doing more things with him when i wasn't around and being extremely more touchy with him and i was love struck which i was pretty stupid back then but back to the story i didn't know it but everyone i knew saw it but i ignored it, but one night me and my best friend had a call she is my ex and best friend we didn't end it bc of a problem but bc i was forced to move away we stayed close and during that call, it started normal with us playing games on roblox as we played we started doing dares and things got spicy i won't go into it but it was a night that gave me a wake up call to start seeing things differently and i was still emotionally connected with my best friend while my ex was physically and emotionally cheating on me i won't lie after that i did regret it, but 2 months later she broke it off with me i was broken and that the time my depression kicked in hard and i didn't want to do anything then they were acting like a couple after a few days of breaking up with me at the time i realized that she was cheated on me and my friends were right and i scrolled back on my friends texts and i saved them so they wouldn't lie about it and at the time of writting this it's been a year i've moved on, only a month or three ago i was told she tried painting me as the villain of the relationship but thankfully no one believed her and i now don't regret that night and i think of it as pay back for trying to lie about me and cheating on me for months i don't know if you think that was the right thing at the time but i think it was, i would like your option on it