In general, Addison's people throw up when they are sick (aka a crisis), not when hungry. It occurs due to the imbalance of sodium and potassium. Do you have abnormalities in sodium or potassium?
A lot of symptoms are general, but the specifics on it is that it is a salt wasting disease. Do you have low blood pressure?
What time are you going for the test - and what test? Normally, you would need several tests of hormones and electrolytes, and tests over time. Since cortisol normally varies, it is good to see a pattern plus get the other hormones as well. Then a stim test.