I can definitely relate. I tend to become very closed up in negative situations too, and shell up, hardly saying a word. It can be tough, as these situations can seem demanding. One thing that has worked for me is asking for a break to process the situation and think of things to say about it. If you allow yourself a few minutes away from the situation, you will be able to think about it without dealing with it dead on, and you can walk back into it feeling a bit more confident of what to say. I hope this helps!
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Given a “tentative” diagnosis as a child as I needed services at school for what was later correctly discovered to be a major anxiety disorder.
This misdiagnosis caused me significant stress, which lessened upon finding out the truth about myself from my current and past long-term therapists - that I am an anxious and highly sensitive person but do not have an autism spectrum disorder.
My diagnoses - social anxiety disorder and obsessive-compulsive disorder.
I’m no longer involved with the ASD world.