Even though you can't hold it down, keep taking those tiny sips. Tiny amounts, enough to wet the surface of your mouth. You must keep your fluids up or you will get very ill very quickly. Take care of yourself.
Edited to say, I slept for the first day and night, threw up for the second day, thought I was dying and regretted getting it done. Felt a little better on Monday, had some jelly but could not hold it down, postponed ferry home and by Tuesday was on the mend.