I see a lot about autistic people talking too much because they don't realise they've talked too long.. But I have the opposite problem

I assume that nobody is interested in anything I have to say, so I find it really hard to make conversation. My mind goes completely blank and frozen (I have CPTSD Freeze). I'd love to talk to people about my interests but I feel like noone is going to care. It makes me really quiet, withdrawn and boring.

Edit just to say I appreciate everyone's responses and I relate to all of you so much, thank you for making me feel not alone