I'm so sorry you're going through this, @Nay1990. Just to give you another lesbian parenting perspective, before our daughter was born, my wife admitted she was having a hard time dealing with the fact that my family would be biologically related to our daughter while she wasn't. (I was both the biological and gestational mother.)
The difference is, she completely understood that this was her issue. And it never raised its head after our baby was born, because she realised that babies care more about who gives them cuddles and love on a daily basis than whose genes it has inherited.
On mornings when I was struggling and my wife had to go to work, she would always ask me to call my mum to come over and keep me company, because she wanted me to have support when she couldn't provide it. Not only was it better for me, it was better for our daughter, and THAT was her priority.
Given your partner is unwilling to work with you on improving your relationship, I would just spend whatever time with your mum that you can.
(Incidentally, as gestational mother and primary carer, you would actually be in a better position where custody is concerned if you were to split.)