Is it normal that going days without food or sleep hurts?

You idiot! The fact that eating and sleeping again stops the pain should automatically tell you what is wrong! Did you seriously not realize this even if it was when you were writing this post.

It's normal. Lack of sleep and food causes the body pain.

Not related to your injury. Humans need sleep as a sort of energy reset. Since you have limited time, i'd suggested napping in sleep cycles if you can; I think 90 minutes is a full sleep cycle, but I would look it up if I were you.

Food is also necessary for energy, vitamins, and just functioning in general. Ramen is cheap, filling, and quick to make, so i'd suggesting making and eating this when you have a few minutes free. If you don't have time to prepare it, then premake it and carry it in some kind of container (same container as soup) to eat for later. The human body can't handle long periods without sleep or nourishment, but you should start doing a little better if you give it breaks and morsels here and there.

You need to take it easy.

Ur body kicks up the pain reception when it's under certain kinds of stress. Being hungry is one of them. The hormones ur body releases amplify nervous responses to pain. I remember when I was a wreck and lived in my bed for a month when my ex fiancé left me in the middle of the night while I was asleep... I stopped eating. Stopped sleeping, and I had this nervous tick that developed, I'd clench my jaw unconsciously, and it started to cause me the WORST pain I'd ever been in. It was blindingly debilitating. I couldn't even open my eyes without being in unbearable pain. I noticed it would subside a bit when I'd eat something. Idk why. But it did. Still bothers me a lot. But nowhere as bad as it once was. I also think eating food has a lot to do with how fast and well pain medications like IBuprophen and codeine are absorbed

Your body repairs itself from the energy it receives from calories and when you sleep. If you have an injury, you need to take extra care not to skip out on these things. Otherwise, your body will have a harder time healing itself. Take it easy.

Its normal to feel that way after you dont eat or sleep.
You need to eat and rest especially if you have an injury! find quick meals...you can even stop by a bakery for a muffen or something to eat during class...bananas and apples are also quick things you can grab to eat on the go....please eat :(