Strange onset of stuttering I can’t explain. Any ideas?

Strange onset of stuttering I can’t explain. Any ideas? Hello everyone! First time posting here but I recently had a scary experience with my stutter and I was wondering if anyone could give some insight about it. To begin I’ve always had a slight cluttering/stuttering issue growing up. More cluttering than stuttering overall but because I was always jumping around with my thoughts there was always an overlap when speaking. It always just something I’ve accepted about myself and people who knew me just understood that I tripped over my words and talked too quickly and kinda just accepted it as a quirk I’ve had so I never really “struggled” with it unless I was writing a paper and couldn’t separate my thoughts so it all came out garbled on the page. That is until the month of my 30th birthday and I finally moved out for the first time which was extremely stressful before I went on a birthday trip with my family that didn’t go well. Lots of stress from family that really dampened the experience and left me feeling depressed. Only for the week after the very person who caused the problem had a major health scare so I was angry at him for ruining my birthday and also terrified by the idea of him suddenly dying. Both emotions co-existing in my head. I couldn’t sleep well that week. Then I get an unrelated anxiety attack a couple days later and I’m in the line at McDonald’s to try to get something to eat to de-stress and when it was time to order I suddenly my stutter comes back and hits me like a truck. I stuttered so badly I couldn’t get any word out. It was so unintelligible they had me go to the window to order and I still had to start over three times before I could even say what I wanted. I got embarrassed because my stutter was never that bad before but that was only a preview. I began thinking about my stutter and doing nonstop research for two days trying to figure out why that happened but I got invited to go out with a couple of friends to ikea for the evening. So I go and because I did a lot of research I thought I would be fine but immediately it was as if a switch in my brain shut off. I stuttered worse than ever. My friend commented on it worried about me and of course my anxiety went up and by the end of the night I could not speak without stuttering every single word in every sentence. I had to purposely pause for a couple of seconds for each word to actually speak and it was terrifying and embarrassing. I felt like I was going crazy. Ikea is overstimulating as is but I never had this happen before. I immediately signed up for a session with my old therapist and she thinks that I’ve had heightened anxiety since I moved out and the onset of stress/anxiety from everything that had recently happened could have been building and building until it came out that night as an onset of exacerbated stuttering. But the strange thing is that it went away the next day (or at least the extreme nature of it. I still stutter but now it’s back to slightly more frequent than my usual). But I still can’t stop thinking about that day. Slightly related but my therapist also wants me to see about getting assessed for autism… I’m mostly familiar with autistic traits because my brother has it so I know that sometimes people go nonverbal if they are too stressed or overstimulated. So my question is this: If your body is telling you to be nonverbal does that result in an exacerbated stutter when you try to speak? Like does the body try to physically shut down your ability to communicate? Or is it more likely the stress/anxiety thing? I’m still new to the idea that I might be autistic but I guess I want to figure out why I couldn’t hardly speak that day. I’m more aware of my stutter now and I’m terrified of losing the ability to speak again like that. Does anyone else relate? My next therapy session is in two days and I’d like to explore any ideas as to why my stutter got so much worse for a day before coming back down to usual. Any insight would be highly appreciated. Thank you so much in advance!