It’s good that you’re taking on board what your therapist has said; coming to the realisation that you were emotionally neglected is pretty crucial to your healing - it’s also really good that you recognise when you’re repeating that (learned) behaviour and making a conscious effort to break the pattern. It’s not easy, as like you said, what your mum did was very subtle. Det var
I’ve had similar issues with my mum, too. I’ve come to realise my relationship with her is actually quite superficial in some ways, because I stopped sharing things with her unless I was desperate for her help, because I got the blame for things that, sometimes even quite obviously, weren’t my fault. I think I’m not really allowed my own feelings at home, either. I’m not allowed to be really angry, for example, at least not if it doesn’t relate to my dad’s alcoholism in some way. But as you’ve realised, feelings that aren’t expressed often just get internalised.
I do think it’s possible to heal, but it does take time, conscious effort and effective guidance.

I think this would be a really valuable fear to share with your therapist in order that you can explore what's going on for you now and simultaneously how it reflects your childhood fears. It sounds very much as if you are describing your feelings about your mother: if I am honest with her or if I assert my true self, will I be too much and so disagreeable that my mother will leave me? If my mother rejects me, I am alone and I am in danger. These are archetypal fears and ancient dreads.