I took Seroquel for several months and had chronic, severe nausea. I weighed about 125 when I began dosing. Interestingly enough, I could only eat Totino's frozen pizzas as they did not increase my nausea. My docs took me off all of my meds and the nausea immediately disappeared. As I was sure that the Seroquel was the problem, I took it one day and nothing else. Bingo. Immediately the nausea began. Naturally, the med was dropped.

As for breathing issues, I never experienced that symptom. For your good, I definitely would call your pdoc immediately and report the issue. Chances are, he/she will have you stop the med or have you come in to see him/her ASAP.
Good Luck

Peacemaker