Yes I had a friend of 20 years that I "broke up" with. And it did feel a bit like an emotional divorce.
We were friends since secondary, at school she was best friends with me one minute and worst enemies the next, she was very popular so I was either completely isolated (once she even physically assaulted me for no other reason than to show off to a group) or the centre of the world dependant on her mood, she would also set me up with boyfriends (usually friends of her current boyfriend) and then make me dump them if we were getting too close or she'd dumped her own boyfriend. The hot and cold continued throughout our relationship, I was often an emotional punchbag, and I did tolerate some pretty horrendous abuse but we would also have a great time if she was in high spirits. She used to also use me as cover whenever she cheated on her husband, which I hated doing, but was too cowed to say anything or refuse to be complicit.
We lived 100 miles apart from our mid 20s onwards, as I'd moved away to uni and was chasing my career but used to always visit her when going back to my hometown. I always made an effort with her but she would also drop me for months on end, on a whim and then communicate with me again when she felt like it.
And then one evening (in my early/mid 30s) I was just sitting watching tv and saw her name flash up on my phone as she texted me, I hadn't even read the message and I had a full blown panic attack just from seeing her name. It was then I realised I just had to get out of the friendship, I sent her a bit of a wishy washy message saying its not you its me but I think our friendship has drifted apart and I think we should call time on the friendship. Wish you all the best etc.
Less than a year later she contacted me again (prompting another panic attack before I read the message) saying her parent was dying and she needed me, her kids missed me and didn't know what she'd done wrong. It felt like emotional blackmail.
I just snapped and sent a long ranting message of all the abuse I'd endured throughout our relationship and not to contact me again. I felt absolutley awful (since she was going through a hard time) but also I needed to get away. I probably handled it terribly but l really needed the relationship to end. She blocked me on everything after that message. I threw up after I sent it and then it properly felt like a weight had been lifted off my shoulders.
I don't wish her any ill will tbf, I hope she is happy. But I am relieved she is not in my life anymore.