Why Can't I Talk During Panic Attacks?

(TW: Mention of self-harm)

Hi,

I have panic attacks, but I've never been tested nor diagnosed for anything at all. Most of my panic attacks are shorter, but they can sometimes last for longer amounts of time and can trigger self-harm in the form of cutting.

Whenever someone sees me having these panic attacks and tries to speak with me, I struggle so horribly to talk back. I can get out little squeaks and occasional mumbles, but I just can't. I can't and I hate it. I try so hard, but I just can't speak. How do I fix this? Is this normal for panic attacks?

I try to bring up my panic attacks to my therapist, though I just can't manage to. I don't know why. Does anyone know what I should do? And the triggers I've noticed for panic attacks aren't avoidable. Some panic attacks just randomly happen, too.