Do I go to the emergency room?

Im 12 wks prego. Since I was 7 wks, ive now lost 27 lbs. and im NOT exaggerrating. I cannot hold anything down, not popsicles, soups, water, teas, smoothies, I mean nothing! Ive been prescribed zofran for nausea, but it doesnt help. I am now feeling really weak, dizzy, my eyes cant focus well, im really hungry and thirsty, and when sitting or standing its hard to catch my breath. Ive never felt like this before. I have been to the hospital one time to get fluids thru an iv. I called my ob and they said they dont prescribe other medicines, and do not want to send me to the er, to just wait to wait til my appt. in 2 days. Do any health experts disagree? Should I go to the hospital now, or just tough it out 2 more days and hope everything will be ok?