Everyone here respects your choice and we'll gladly help you however we can.
I did want to point out, however, that you're absolutely part of her cycle. Everything that happened with you/her also happened with her ex husband. She cheated on him with you, and cheated on you with him. Likewise, she bad-mouthed him to you, and she probably did the same to him (about you) when she was feeling vulnerable.
That's the mental illness part of this entire equation, she's unstable and making bad decisions.
If you want to continue the relationship, then it sounds like the door is at least partially open still. When is her birthday? Talk to her directly before that. Since she's planning on you spoiling her, she might not even realize how far the relationship has deteriorated. Again, that's the mental illness part of this, with her mind being pulled in many directions at the same time.
Her birthday was in February—exactly a week before mine. So that topic kind of passed already. But something strange happened last week.
About 20 days ago, she asked for a pair of pants she had left in my car. I had left them with one of her family members. I also had a coat and a sweater of mine that I had gotten while we were together. She said I could take them back, but I didn’t. Because honestly, I didn’t want to.
Then last Friday, on the night of April 12th around midnight, she texted me. Before that, all our conversations were purely about Facebook ads, as I mentioned—nothing personal at all.
She asked why I hadn’t picked up my things. I told her I simply didn’t want to. Then she said the following (I'm sharing the exact messages):
Her: Why didn’t you get your stuff?
Me: Honestly, I just didn’t want to. It’s been a while anyway—why do you ask?
Her: I wanted to ask, but couldn’t. Never mind.
Me: Why not?
Her: There are many reasons, but now isn’t the right time to ask. Still, I was really curious. They were yours.
Me: Now I’m curious about all those reasons. Can you tell me?
Her: Replying to “Now I’m curious about all those reasons. Can you tell me?” Me, and the things I did.
Me: I think you can go into detail—we can talk openly.
Her: Just assume I didn’t ask. Never mind. I’m sorry for bringing up weird stuff in the middle of the night. Please forget it.
Me: You know I don’t forget things like that. I don’t think it was weird at all. You can ask—actually, I think you should.
Her: No, I’m really not ready to talk about these things—about myself, I mean. I’m sorry. It’s not the right time. I brought up a pointless topic and texted. I’m sorry.
After that, she kept messaging me throughout the week—again, about work stuff. But the small talk continued too, and she kept using heart emojis. I didn’t really sense anything from those messages, but somehow it all felt… real? Though I can’t be sure. Maybe it’s just her usual behavior pattern.