I think that you are identifying part of the major issue a lot of people have with CBT, including me. It's also the reason that traditional CBT doesn't work particularly well for people with borderline personality disorder, chronic depression, C-PTSD, and a lot of other problems resulting from childhood trauma. It's also one of the reasons that DBT was developed, (and possibly ACT, but I don't know much about it.)

DBT acknowledges that thoughts affect feelings, but the whole "rational" or "irrational" thing is not part of it. DBT says that every behavior (or thought) has a cause. Sometimes we know what that is and sometimes we don't, but there is a cause. So for example, one of my deep beliefs is that I need to stay quiet and hidden or I will get hurt. You can try to rationalize that away all you want but since that was my experience as a kid, I have that belief. And when I was a kid that belief and behavior made perfect sense. So it's important for a therapist to validate that, and frankly for me to validate that for myself. But does that belief make sense now given the *current* facts? And is it still helpful or effective for me? Not really. So I'm trying to change it, but that doesn't mean that it isn't there for a reason.

What you are describing sounds like therapist invalidation. That's harmful. Trying to convince you that you were not abused or gaslighted is not helpful at all. You were a child and you were hurt. No amount of rationalizing that it wasn't "bad enough" or anything like that won't help. In fact it's more hurt.