How to set boundaries?

So I live with my dad, my fiancé and I rent his basement but I make suppers for him so we eat upstairs. Anyways I’m trying to feed my daughter, and we’re doing baby led weaning but my dads girlfriend came over and offered to feed her while I cleaned up supper so I said sure. Well she’s gone and pureed the food even after I said no, she’s currently gagging which I know is normal but they’re hitting her back hard thinking she’s choking. I try to say anything and my dad yells at me, we’re currently shopping for a house to buy as our previous rental was in a different town and we needed to move to a larger city, so moving isn’t an option right now. But I’m at a loss of what to do. I constantly get yelled at for raising my daughter and I just don’t know what to do.

Any help is appreciated

Edited to add- every time my dads girlfriend comes over they take over parenting my daughter and I have to sit in silence. Sometimes when she comes by it’s literally hours before I get to see my exclusively breastfed daughter and when I say it’s time to feed her or change her I’m told she’s fine and she’ll live. 🙄🙄🙄🙄