This is and all the posts from so many people being treated this way by their own parents is so utterly heartbreaking. I am so sorry.
It is emotional abuse. She is vacuous, superficial, judgmental, cruel, manipulative, gas lightning and rewrites history and minimises her role and words when confronted.
Her love is conditional not unconditional as you have for your own Dd as it should be. Most parents would never dream of this treatment. Some parents may say things clumsily now and then perhaps believing for health reasons they may be helping, but not this. That is evil projecting, wearing down your self esteem as a way to control you and make herself above you.
Absolutely she is projecting her own issues onto you. I am glad you see it and are finding some strength to stand up to her, and getting some counselling. I agree writing diaries or letters to yourself about your difficult upbringing and relationship based on this chronic and unjust mistreatment, to pour your memories and feelings on to paper can be cathartic, and re read them when you are not feeling as strong or start to believe her, read them and remind yourself this is her warped view of you. Please don't allow yourself to see yourself through her twisted lense.
She truly sounds like a classic Narcissistic personality disordered Mum. They often obsess about their daughter's appearance and weight.
It is near impossible to reason with them. Narcs don't naturally feel empathy, they protect their own weakness and shame as they have inside but dare not show it on the outside. If you call out a narc they will completely turn it around on you, and make themselves the victim, i.e. How dare you after all that I have done for you financially and any other support, a loving parent helps their children with these things in life with no strings attached, and don't use it as ammunition to throw back in your face when you quite rightly defend yourself and your Dd and call her out on her unacceptable behaviour.
There are lots of websites with in depth reading on this personality trate and behaviour, support groups, blogs, books, pod casts, YouTube videos who educate you on what this disorder is and entails, the behaviour is so classic and predictable you see others write stories almost identical to your own. However there is plenty of help on how to interact with them whilst minimising the damage to yourself, help you understand and come to terms with and give a name to what you have been on the receiving end of your whole life from someone who is supposed to love and protect you more than anyone. There is terminology used like things such as going grey rock, or how to lessen your contact, or go no contact if they continue to hurt you despite firm boundaries and warnings. There is only so much you can say and do, it is important you protect yourself and your child from being the next generation affected.
If you read up on Narcissistic personality disorder in Mothers and do not relate, think maybe it's not as bad as all that, then it may just be a lesser Narcissistic trate rather than full blown personality disorder. In that case there could be hope you can get through to them. Still learn the teqniques to equip yourself.
I found licensed clinical psychologist Dr Ramani on YouTube very helpful, warm, and insightful, also especially read the comment section on their as it opens your eyes to real stories just like yours, and helps you feel a lot less alone and a lot more sane. Dr Ramani has many videos as she posts regularly on all aspects of NPD Narcissistic personality disorder.
Link for her: m.youtube.com/watch?v=VedPxLtgcLE
I'm glad you clearly have a loving, understanding Husband in your corner. Best of luck with everything. 