Anyone else on Rexulti? What are your experiences?

For some reason 2mg caused me to not be tired, getting 5 hours of sleep at most.
Now on 3mg I'm tired all the time. I sleep from like midnight to 1pm. And I'm so tired throughout the day that I take like 3 two hour naps a day.

What gives? My pdoc says that this med has proved to work the best so we're sticking with it. I want something new..