AITA For dumping my "friend" after constant toxicity and mocking my disorder?

I've been friends with someone that I'll call Ell, for the sake of anonymity. We we're friends for a while, since 7th grade even. So it's been 3-4 years. Things had gone somewhat smoothly up till 8th grade when I had asked her out. She said yes, which was nice at first, but then she became EXTREMELY clingy. She wouldn't let me hang out with anyone that wasn't her and would get mad if I did. We were off and on for a long time, up untill this year. Whenn she decided to try a polyamorous realtionship with me and my partner. But it was later revealed it was only for her to get closer to me. Ell wanted NOTHING to do with our other partner. Now fast forward to the beginning-mid 2024 when I get a DID diagnosis.

We had maybe had 10 alters at the time and were still trying to figure things out. Ell starts acting very different around us, more angry than usual. I asked her why she was so angry, and she retaliates, asking me why I was faking such a heavy disorder. Mind you, I'm not like that, as I have friends who truly struggle with such a disorder, and I've seen how bad it can get. There are identity struggles, breakdowns, loss of self. Its a lot and I would NEVER fake such a disorder.

I looked at Ell, completely hurt and asked her why she would ask such a thing. She told me it doesn't just pop up out of nowhere, and I couldn't have it because I don't have enough trauma. That isn't the truth either, as I've told her there's much more that I choose not to voice.

She then began to question how I got so many alters in such a short time. Well, we have a low split tolerance. In basic terms, the brain can create more alters faster than some systems. It's pretty normal. I tried to explain that to her, and she rolls her eyes and mocks me further.

There have been times where I've tried to cut her off, but she makes it extremely difficult. I ignore her, I tell her to leave, other alters have switched and said the same. She just follows along and acts like a younger sibling would when we tell her to leave.

Yesterday was the last straw. I started to feel really dissociated, like I was about to switch. Things got really fuzzy, and I could see Ell leaning over and looking at me. In a mocking tone, she looks at me and my friend at my side. She goes "Oh. Look he's switching. Oh yeah and Delivery God Yato now~" I want out of this hostage friendship so bad. She's gotten on my last nerve

AITA here?