With the racing thoughts- you may want to consider googling mindfulness and try some of the exercises there. Also for me- playing cell phone games like Words with Friends, Rush Hour puzzles, Bejeweled can temporarily slow my mind down. Running and taking long walks seem to help as well. Unfortunately, reading seems to accelerate my racing thoughts- but for some people- it will help.
Keep in mind that with any medication switch- it may take up to a couple of weeks to become effective so you will need to come up with some strategies that can help to bridge the gap.
For me- Depakote has worked the best for managing my manic symptoms. I originally started on 2000 mg due to the severity of my racing thoughts but I was able to taper down the medication to minimize the side effects. It did take me almost a year to go down to 250 mg. The combination of Depakote / Zyprexa did make me put on about 25 lbs- but I was able to lose the weight by going off Zyprexa and gradually lowering my Depakote. I know that no two people have the same reactions- but if you describe your symptoms (including your physical symptoms- how well you're eating, specific moods), then the more likely it is for your pdoc to identify the optimal medication for you.
Good luck and let us know it goes! It does get better!