For sure it could be lack of sleep and food. When my anxiety is really bad, I eat a lot of granola bars or any other meal replacement bar that tastes good. It really helps me keep up my nutrient intake. For water, I drink calming teas and I put water in a glass water bottle. Also, to help sleep, I drink the tea 4 hours before bed. If I drink it right before bed, I am super sleepy the next day. I hope you can get some rest.