I cheated.

This will be a long rant but I chose this day to vent it out. Just wanted to tell my situation to someone and confess what I had to say.
I (M) was in relationship of 7 years with my girlfriend (ex). We were doing very fine. It was my very first relationship in my life. I have had crushes before but the relationship was first. We went through our college days together. She was the sweetest, loving person I have ever met. She did everything she can do, I also did for her(I think).
Down the line. After maybe 4-5 years I felt like the relationship hit the plateau phase. And at the same time we had to deal with the long distance relationship as well. We still kind of doing fine. She used to call me most of the time, asking me about my whereabouts and my day. During our long distance relationship, I had few colleague friends one of which was a female for names sake say “A” (committed). “A” had ups and downs iin her relationship, and used to tell me everything about it. I used to verbally console her and would tell her that everything is going to be fine etc. I mean I didn’t try to hit on her and it did not even cross my mind.
(After maybe one year of our long distance relationship ) I went to a group party one day with all my colleagues, one of which was “A”. We all were drunk. As it was late night, “A” said she couldn’t go back home so she asked me whether she could come to my place to which Isaid yes. I didn’t even think about doing anything wrong. But after some time we ended up having a make out. It was very uncomfortable situation for me and her. I didn’t think about my current girlfriend, I was out of my mind. My girlfriend was sleeping peacefully at her own place and here I am, the most disgusting guy cheating on her with my colleague “A”. It was very much disturbing night for me. But in the following days, she invited me to her room, we ended up having sex. i was not thinking with my brain but with my d**k,the most disgusting thing I have ever done.
One of our mutual friends got to know about this and told my girlfriend about it. Obviously she broke up with me. She didn’t even listen to me. She literally tried everything in our relationship, she was positive, she was sweet, caring and what not. Probably the perfect girlfriend anyone could ask for. But here I am the disloyal, disappointing boyfriend who slept with a girl (A).
After that phase, I have tried everything for 1-2 years I could in my hand, tried apologising her, literally beg her to forgive me and come back but obviously nothing worked. She was shattered, cried infront of me, that was the worst day in my life till date, seeing her cry.
After 2 years of breakup, I still have not recovered from that break up. I want to just apologise to her but I cant, theres no way to talk because I am blocked from every possible platform. I want her to be happy, maybe I was not the one. And definitely she dodged a bullet for sure. I hope she gets everything she deserves. Everything is going “okay” in my life but I still feel the big void which is never going to filled by anyone. I wish her all the happiness in the world. I wish she gets a better partner.
I am disappointed in myself. I am depressed, feel like killing myself and I hope I do one fine day.

TLDR- I cheated on my girlfriend. I’m very disgusted about myself.

I am ready to face all the bashing/downvotes from all of you. But please wish her happiness, the only thing I want.
Thank you for reading.