AITA for being annoyed at the fact that I share a friend group with my ex?

If I could be totally honest about something, it would be about the fact that breaking up with someone is the WORST thing ever. I'm not saying this in a way like "oh, I loved so badly", because that's not the topic I'm talking about right now. I'm talking about how FUCKING TERRIBLE!!!!! It is to break up with your partner when you have a whole ass friend group with them

For starters, this happened a few days ago. I broke up with my ex because I realised I didn't have the health to maintain a relationship, and so did they. I sent them a long message explaining the situation and that they didn't owe me anything, that I just didn't want to cause more harm than good maintaing a relationship with them. They accepted this "properly"—in quotations marks because they DIDN'T TAKE IT WELL, AT ALL. Which pisses me off a ton

(For previous context, the reason why I'm pissed off is because we broke up and went back together THREE OR FOUR TIMES, BECAUSE OF THEIR DECISION.)

I believe now all their friends hate me. Some of our shared friends understand my perspective, but they quite of feel saddened of the fact that my ex was "really good" and stuff... And the fact that they act so much like a poor lonesome person who no one loves, when we ended up the relationship IN GOOD TERMS???

(Note: I should've broken up with this person before, because they cheated on me with their ex on January. I just let that slide because I had to maintain the friend group together)

So, if anyone can please answer, I'll be glad to read any sort of comment!!! ^_^