Sick of being sick

Last night one of the Americans invited me along to the Sheraton for drinks and some food. Initially I declined because I lost my wallet on my 2nd day here and still don't have access to my money but he offered to shout me so I couldn't say no. So we went to this oasis of luxury and class in Sana'a - I ordered lamb kufta and had two vodka and oranges. Now good sense would tell you to never eat the ice in a foreign country, particularly not Yemen. But I overheard someone say that the ice at the Sheraton is fine to eat and I believed it because I wanted to and ate the ice in both my drinks. Within about an hour I had a fever and 2 hours later I was back in my room shivering in bed with 2 jumpers on. The next morning I vomitted but was determined still to go. I dragged myself and my bag downstairs but eventually I had to give up on the idea of going because I could see myself stopping the bus repeatedly on the 10 hour trip so I could vomit. So yet again I've missed out on a trip. I know there will be plenty more opportunities to go on these trips during my 1 year here but I have serious cabin fever lately and getting sick all the time is making this a horrible experience. Today I slept all day and woke up with a headache but feeling a bit better. I think by tomorrow I'll be feeling fine again but I will not be eating out for while.