Should I go on a higher dose of Xanax XR?

It happened a year ago, my junior year of high school right before I was about to board a plane for a trip with my school, a panic attack, at the time I had no idea what was going on, my world was crashing down, I was unable to board the plane, it was one of the worst times of my life. I was diagnosed by myself with Panic Disorder and Generalized Anxiety Disorder, I soon went on Xanax XR, and all was good.... or so I thought. For a month or so everyhting was good.. I shortly after collapsed in trembling panic attack at the movies but they were very abbreviated incidences. It took me a while but I soon came to realize I was always tired in the afternoon after getting home from school. I soon experienced one or two minor panic attacks and its been a dull nausea pain ever since.. including sleepiness, dizziness, heart pain, head aches, stomach problems, etc..... this is to ask should I go on 2 MG of Xanax XR or should I just stick it out? any help is good thanks!