"She says she doesn't mean these things in a nasty way just having a conversation is what she said (and then the whole speech of i won't say anything again then I'm not allowed to talk ill sit in silence) 🙄"
Kind of thing my mum would say because she can't possibly say anything nice or keep her unsolicited opinion to herself.
Then she turned your hurt response round onto herself and played the victim to try and make you feel unreasonable/bad for being upset by her unkind comment.
As for the whole speech of 'wont say anything again, etc' your only response to this in future should be "glad to hear it, if I want your opinion I'll ask for it", or, "if you can't say anything nice, say nothing at all" followed by "I don't want to hear your justifications for saying nasty things".
She knows you're sensitive about your weight and she needlessly hit you where it hurts. That says more about her than it does about you or what she actually said.
Have a think about it, the times she's critical of you/your family versus the times she says nice things. I bet there's a pattern or she's always been like it and now you have your independence and life of your own, I'll put money on her resenting that and wanting to make you feel as miserable as she does instead of being proud of you.
Well done on the weight loss, that is a brilliant achievement and bollocks to what she says. Time to care less about her opinions I think or call her out on her thoughtless comments. Each. And. Every. Time.
Christ, sorry for the essay!