Hi Joy
I remember severe nausea side effects when taking
erythromycin, a similar antibiotic. Make sure you have something to eat (ideally your main evening meal) before taking the pills and then wash down with a glass of milk and see if that improves things. I found that antacids helped as well.
You will find information on side effects on this website
Try
http://biaxin%20xl.drugs.com/ and
http://www.drugs.com/PDR/Biaxin_XL_Filmtab_Tablets.html
The dizziness is described as a common side effect of
Biaxin XL. Anxiety has been known to occur and resolved when the drug was stopped. Hopefully the Biaxin XL course is relatively short and you can take some time off to rest. Take care.