I am a "favorite person" survivor

TLDR: i was everything to somebody and now I feel discarded and ignored.

I befriended a person. Looking back I see so many tell-tale signs. But I've never heard of BPD before.
First thing I noticed was her very Black and White thinking. I even had some conversations with her about it, calling it exactly that, again not knowing her condition.
Then the love bombing began. Jesus Christ, her absolute obsession with me was unlike anything I've ever experienced in my life. We did date for a couple months. She had a very odd, and unhealthy relationship with sex. She really enjoyed borderline violent practices and had a very strong sexual appetite.
She would regularly send me photos of herself and send me images of her journal where she would write long love poems about me. In fact at one point she had been practicing her signature, with my last name, over 300 times. I did think it was strange and it kind of made me uncomfortable because of how she treated me like a celebrity. Constant texting. Every single day I would wake up to see texts from her late at night the night before AND from earlier that morning. Again it was a strange but it felt really good to be thought of so much. We had a clear break-up although agreed to remain friends.
But the constant invites out, the incessant texting.. the strange celebrity status she treated me with became exhausting. I began to notice she was very sensitive to how i responded via text. Sometimes when I was at work I'd only be able to respond with short messages and she would freak the F out and send me long dramatic paragraphs of a text message, calling me an asshole. I soon learned that my mood, my vibe would always set the tone for her day. She also had severe, i mean extreme mood swings. Her sad days were concerning, as I'd sometimes go to her aide, again she'd be texting me about her sadness, to find her in her dark tiny apartment listening to sad music. Really embracing her sadness. But it was very... haunting to me.
Anyway once I learned how to treat her I shifted my mind into caretaker mode... It was the only way to survive her.
We'd hang out almost every single day doing all kinds of things. And there was a lot of fun, but I always felt like I was walking on eggshells around her. And everything we did was on her terms. She was very close-minded about ideas that weren't hers, and I noticed she manipulated me and others around her in a selfish way.
But after 12 months I was completely exhausted and I began to feel a sense of resentment. She would do things that even a normal friend wouldn't get away with.
And she was very emotionally unavailable when I need her to be there.
The entire relationship was one-sided. But I was afraid that if I were to tell her these things she would explode, go into a fit of depression, or worse.
So I slowly pulled back. Waited to respond to her messages. Decline invites to hang out. Stop frequenting places she could predict I'd be at.
We kept in touch, although much less.
But I see her doing this to others. I see her attempting to have sex with other people I know. And it's embarrassing, sad, and painful to watch. I'm so sick of hiding her secrets.
But I do miss the good times. She once told me "I love you more than anything in this world". It hurts.
EDIT to add: last year she had planned a massive birthday party for me and showered me with gifts. PLanned the entire day with non-stop activities. She had obsessed over my bday for weeks. Made me feel like King of the World.
This year she hasn't even asked me if i have plans for my bday and it's tomorrow.