Have you ever lost yourself in riendship?

Have you ever lost yourself in a platonic relationship? Have you ever dealt with a narcissistic best friend or similar? What has been your experience? When did you know it was your breaking point?

I walked away from my best friend a few months ago because i felt like the relationship was surrounded by such negativity and insecurity. I feel i could've ended things better rather than just texting her " Im done" because of a Facebook post about being grateful for all of my friends and she didn't want me to have anyone but her as a friend and she just deleted every interaction we had. I thought, were too old to be playing these games. I noticed that she would keep tabs with me on social media hyper religiously. I apologized for things i shouldn't have. I apologized for having healthy relationships that were not with her. I apologized with going to events with friends so we would go to those events again just to please this person. I let them crash on my couch only for them to complain to others i never gave them a bed. Too much to say and not enough life left on my laptop keyboard hahaha.

Just for clarification, this wasn't the reason but the breaking point. I just cant get rid of thing pang of guilt but also the need to go to therapy because of this.