@bolfun4k So, you can be supportive of DH and not have a relationship with his mother, as long as he is respectful! He could say "gah she was annoying and rude to kiddo!" And you go "that sucks honey".
This sounds more like he knows she's hurting kiddo because she's mad at you, and instead of protecting his kid he's blaming you, even though it actually has nothing to do with you?? Wtf? That's a dad fail right there. Wife, kids, then everyone else.
Also, ask him why he's ok with her being beyond disrespectful to you, the marriage you share and
both of your parenting abilities? If he reckons respect would fix this why doesn't he realise it shouldn't ever go one way?
I'm so sorry you have to deal with this shit. I know I don't have your patience, and I would not have kept offering food! Does he not get he is hurting you by putting the blame for everything on you? He's your DH, why is he hurting you to try and make someone else feel better?