5 days ago got nausea & stomach cramps. now, no appetite, head feels like pressure, no bowel movements for 5 days, moderate fatigue, insomnia. no feve?

You could have an: infection. HAve you been drinking enough fluids? No BM for 5 days is not a good sign. You might want to try some OTC product to help you have a BM. Stay hydrated, rest as best you can, eat well (something) even if nausea, your body need energy. If your not better after a week consider seeing a doctor to help evaluate your symptoms.