How to figure out the root cause of unwanted obsessive thoughts about a new platonic attachment?

I started making a friend in the beginning of this year and it's gotten to a point where my happiness very much hinges on her contacting me. I don't like this and want to grow and view this relationship in a healthy way.

For context, I (30s F) am happily married to my wife. My new friend is also queer and happily married to her wife. As far as I know we both grew this friendship quickly, but platonically. She has CPTSD and is maybe AuDHD. She pushed a lot of emotional intimacy in the beginning by oversharing. I have determined in the last few months that I have disorganized attachment. Worried I might have undiagnosed OCD or maybe my ADHD meds are dosed too low. I have obsessive ruminating thoughts about her and our friendship a lot.

We sometimes have miscommunications and I have definitely lost my temper because I perceived her to be rejecting me. She knows I am fearful avoidant which has helped us smooth over the arguments for the most part.

I'm not sure what's the CAUSE of my obsession with her or needing validation. I lost my childhood best friend recently and I think the void of not having that close person in my life and seeing my new friend as a potential new BFF might be at play? I got attached, which is hard for me, I'm not attached to very many people in my life. I want to be friends but not 1) wake up wondering if she texted me, 2) worry she's going to abandon me, 3) wonder if she is mad at me or likes her other friends more than me, etc. Is this limerence? Should I just walk away? I'm confused and sad. This has been really hard.

Please help.