Well done with your jobs!! thats great :)
When I first started panicking I had the same fear and my weight plummeted. It was a vicious cycle because I would fear eating and then fear fainting or getting sick due to not eating!!
First thing is that food won't make you sick unless it is bad. Things like cereal, breads, pastas, vegetables etc etc won't make you sick and any food you prepare yourself will be fine because you know you are clean!
Stomach upset is a part of panic/anxiety, we all know that feeling of butterflies and nausea that everyone gets when nervous. Have you ever thrown up? It doesn't last forever and you do get through it no matter how uncomfortable it is. Remeber, challenge those negative thoughts!!!
I think you should start off slowly, don't force yourself. Have a slice of toast for breakfast and a sandwich for lunch (I find breads actually calm my stomach). Drink lots of good stuff like natural juices and milks. Try to avoid things that could make you sick like junkfood and fast foods. Fries are another favorite of mine, salads I prepare and vegetables. Once you get into an eating cycle you will become more adventurous and get back into your meats and eating out etc.
Hang in there and never be afriad to talk to your GP or cousellor/psych about your fears!!