Feeling weird

All day since I’ve eaten breakfast, I’ve had this headache and this weird nausea. My stomach hurts, and i feel like it’s twisting and turning and just tightening on top of that. Not major, just enough that I can feel and it’s makes me nauseous. Every now and then I get sharp pains in my stomach/pelvic/vagina area. Also my back has a dull ache when normally my back is in a lot of pain. Could I possibly be dehydrated?