I Have Had Chronic Nausea For 10 Weeks, Feel Weak,

I have had chronic nausea for 10 weeks, feel weak, have lost 15 pounds unintentionally, and vomited for the first time today. Do you have any thoughts about what is going on. My thyroid was tested, and it is normal. I was also tested for c-dif and h-pylori a week ago & don't know the results yet.