Extreme Sickness - Can't keep anything down

So I'm 7weeks and 4 days. My neausea is worse than I ever thought it could be. A day ago I did nothing but throw up constantly for 19 hours, I couldn't keep any food or fluid down, since then I have barely eaten as anything I do eat comes straight back up or near enough comes back up and I'm gagging for the rest of the day. Ginger biscuits don't work and my stomach turns at the thought of anything and everything. I can't get in at my doctors and I have no idea what to do, I don't want to go to the walk in centre as I find it a waste of an appointment and time. 
Twins run on both sides of the family mine and the fathers could this be a contributing factor? 
Does anyone have any advice?