Why am I having such a hard time with my mom?

I know she is really trying to make me happy, but all she does is make me miserable. First off, I have anxiety, and she can't comprehend that I'm not trying to be irrational; that's just how I think. Then she will act like I'm being mean and taking stuff too seriously when I get upset, but I can't help it. I also lost weight in the fall to the point where I was unhealthy. I started seeing a nutritionist, and she says I am at a healthy weight, but my mom doesn't believe it. She will go and buy food that she knows I like and she won't eat it so that I feel like I have to have it just to let it not go to waste. She knows that I had to gain weight, and even though I am healthy, it's still hard when she will eat barely anything (no carbs), but I have to force food down my throat even though I am not hungry just to eat enough. Then she practically brags about how she doesn't like to eat this or she doesn't like that, and it's really upsetting because I feel like she is rubbing it in my face. I hurt my hip, so I can't go running, but that is how I relieve my stress. It's all building up inside me, so I keep getting stomach cramps because I have nowhere to release my frustration. I'm just going crazy and I don't know what to do!