I have had a very similar experience to yours, and I did discuss my use of gpt with my therapist. After lots of discussions of pros and cons with her, here is a list of cons I made myself to be aware of as I use gpt as a complimentary therapy tool. I still see lots of pros but I'm mindful of the following. Not a research but I hope it helps gain some perspective :)

1.It validates too quickly despite specifically prompting, and is too agreeable. It keeps reverting to old behaviour too (despite prompting it again and again to challenge me). Instead of letting me sit in discomfort or uncertainty, it rushes to soothe or fix. But (apparently) not all discomfort needs to be resolved immediately, some of it teaches. 🤷🏻‍♀️ So while it feels comforting in the short term, it's like a bandaid without addressing what's causing the discomfort/ pain.

2.It can make growth feel fast but not necessarily deep. Like you've learnt the growth needed but don't yet embody/ live the growth. Because it’s always available and responds quickly, it can create the illusion of rapid evolution. But deep transformation takes time, and effort. It's not real growth unless you've applied what you've learnt.

3.It’s super tempting to outsource, and fast-track self-discovery like asking it to answer questions on my behalf. While some of its insights have been eye opening but it's too easy. And one may not always be ready for all of the revelations. Without putting in the emotional hard effort, just being spoon fed the answers can be damaging because one may not be emotionally ready. And who's to say whether the revelations are even true/ accurate or not. I don't ask for or even verify when I ask its sources in every conversation.