Dehydration makes nausea worse. If even the water is too much you could try with some ice chips and so forth, but this needs attention now. Severe dehydration means you can't urinate which is hard on your kidneys, you probaly can't sweat, dizziness nausea, loss of consciousness and sometimes death. If you can fix it yourself then you must start now, if you are too scared or unable to fix it yourself, you need to go to the hospital regardless of what anyone else thinks.