Controlling Mother

So, my Mother lives in my house. Since she found out that my husband and I were expecting, every time someone would ask her if she was excited she would say, "No, I'm not ready to be a Grandma". Also, when I initally told her her reaction was, "You're (older) sister is supppsed to get pregnant first". So, to say the least, I was very weary my entire pregnancy about how our relationship would be after my baby was born but was hopeful that once my LO was here she would change her attitude and our relationship would get better.

Nope!!

She has turned into a worser controling and selfish person and I don't know what to do. She will only try to help me when my LO is screaming when she knows he is going through a phase right now where he just wants and needs me, he won't even go to my husband sometimes who is very attentive and involved. She takes it personally like my LO does it on purpose to make her feel like shit. When it comes down to dinner time and house chores, she expects me to do it when she wants it done. For example, she expects dinner to be ready at the same time every day even if it cuts into my LO's feeding time and I can't get around to cooking because I am busy with my baby so she ends up cooking, I apparently use and abuse her she told me. That is just the tip of the iceberg. I don't know what to do or say. Every time I try to explain that I am busy and I will get to it when I can she takes it as a personal assault and storms off crying. This isn't a healthy environment for my LO and she can't afford her own place. What am I doing wrong? What can I say to make my relationship with her more stable? This is the only grandparent my LO has...