I could have written most of your post myself, single mum, professional, good functioning on the outside, good at reading others and meeting their needs, but when it comes to "me" I don't have a clue.
Early on with my T the younger "me" was mentioned (by T) - I have a strong loathing for her and in my head could easily destroy her - since then realise I have a lot of negative emotions towards her, including feeling threatened by her (too long to post) - so I really get that feeling of despising her.
She has been off limits to talk about, but recently on my retreat I did some meditation and made myself think of her and to try and feel kindness and compassion to her - she was / is afterall only a child.
I suddenly became very emotional and did for a few seconds experience some warmth towards her. Since then I am back to wanting to push her well away from me, but I guess my experience at least raised the possibility in my head that I can have a different relationship with her.
I think in order to resolve that "self hatred" then it has to get worse for a while with T - for me it is hard to look at her and of course I am going to therefore have some negative emotions. But I hope in time that I can slowly make friends with her with T's guidance and then I hope that my life will start to feel more stable.
You may want her to disappear, but maybe it is significant that she is taking up more space in your head right now. I believe that things come to us when it is time and we are ready to look at them - it might not be easy, but maybe this is going to be a significant time for you.

Soup