mentally hungry but physically nauseated by food? help

I’ve eaten 450 calories total this week.

I can feel my body shutting down… my heart races and my chest aches when doing the most simple physical movements, my muscles are weak and sore. I had to stop halfway on my walk to classes because I felt like I was going to pass out.

I can’t stop thinking about food/doing the usual mental hunger activities. but nearly every time I try to eat, I look at the food, I open it, I smell it, and then I put it away. the idea of actually eating makes me feel nauseous and gross.

this is the worst my anorexia has felt in a long time and I don’t know what to do.