NEVER EVER mess with the dosages of your medications without talking to your doctor first. It is more likely that you have developed some anxiety versus yiou being misdiagnosed, or you may have an addititonal diagnosis of an anxiety disorder, on top of the bipolar. Anxiety can also be present as part of the bipolar process.
You need to sit down with your doctor and sort this all out. There are plenty of medication options out there.
Let us know how you're doing!