You absolutely deserve to have those feelings validated, Partless. You have articulated what it was like to be that small, helpless boy so well, I can feel it with you just to read it.
The idea of bringing your T to that time in your life is a really good one and something that you could explore in therapy.
I hope you show this fantasy to your T. You are well attuned and compassionate towards your younger self, and there is scope for really good work in therapy there. (for grown up Partless) and (for the terrified
little boy you describe)