Theoretically, there is a diagnosis called bipolar mixed, which I may have. I was originally diagnosed with depression and generalized anxiety disorder. The reason my pdoc thinks I may actually be bp mixed is that I have no reaction, or the opposite reaction to, antidepressants that are supposed to help with depression and anxiety. Bp mixed doesn't involve mood swings, but rather, you experience your depression and mania at the same time, which can cause your mania to manifest itself in anxiety, irritability, aggression, etc. After I did the research on my own, and after trying multiple antidepressants, lithium and Xanax, I thought I may have this condition. The research I did led me to believe that a combination of Seroquel and Depakote would help with the anxiety and depression (I, unlike you, am extremely anxious, irritable, and can blow up at the drop of a hat). I discussed this with my pdoc and he agreed that I may be correct. So far so good.
As far as Seroquel goes, it is an antipsychotic and the therapeutic ranges I found on the internet were 400mg - 800mg daily in divided doses. I currently take 100mg only at night and it knocks me on my ass. I also have difficulty waking up in the morning. I took it once during the day and had to close the door to my office to take a nap. That said, with the 100mg of Seroquel, I also take 1500mg of Depakote (an anticonvulsant) at night, which is also sedating, and 4 mg/day of Xanax (more sedation), which I am tapering off of. I have found Seroquel (or the combination of medications) very helpful in both the depression and anxiety I was experiencing prior to the medication, and boy has it helped with the insomnia. Both Seroquel and Depakote are used to treat acute mania, among other uses. It doesn't sound like we have the same symptoms, but just thought I would share my experience with it. Good luck.