Not all people get the bulls-eye rash. I know they often use a blood test to see if you have it, but as you've said it was negative.
What kind of "sick" have you been? Lyme Disease does have flu-like symptoms, but can also lead to things like arthritis and impaired motor functions.
Is there any way to ask your doctor for the antibotics to ease your state of mind? Have you had multiple tests or seen more than one doctor?