I took some xanax last night to go to sleep, an about an hour later, woke up short of breath, feeling like I was going to vomit . I sat in the bathroom on the toilet, and for about 15 minutes or more felt very weak, sick, lightheaded, and feelings of extreme vertigo . Eventually I crawled into bed and passed back out. Needless to say I am very scared and don t know what caused the reaction. When I started my day that morning I took a multi vitamin, some CLA s and a thermogenic. I also took some protein in the morning and after dinner. I am not gonna take xanax anymore, but was wondering if there are known side effects for these things.