Your title is like a line from a poem. I would say not to stop the thoughts, but to write them down. As long as they aren't dangerous, I don't see why you couldn't use the creativity.

Possible trigger alert

The last time I was manic, I decided that I would live my purpose on Earth if I were to die. By my dying, I would be spreading some type of messsage for the whole of humanity.

Fortunately, I wrote everything down, showed it to my T who told me that I should go the the hospital.