I've had the word 'chameleon' thrown at me a few times in my life as I too adapt and change to suit others, to fit in, to meet expectations.

Haven't really got an answer for you as I'm still working on it with my T (She believes it's based on passed trauma and others issues that I'm to be screened for). I would however explore this with your T... ask why she thinks you're doing this rather than 'just stop doing it'... that way, once you have a better understanding (from her side too)... the latter will become clearer and perhaps achievable.