You're welcome -- thanks for reading!
I write across the African-American and European classical traditions, so I can stretch from writing for church and community choirs all the way to symphonic pieces, although I have never had time to write a symphony, and not even a piano sonata since graduating. I am a pianist and singer.
I think that we creative people are more emotional because we were made that way in order to respond to Creation in a way that continues creativity -- the question always is, what do we do with our "excess" capacity for emotion? Will we create good or destroy it? Will we fight against evil directly, create ways to protect and strengthen and rescue others in the fight, or just become servants of evil ourselves? The answer to the questions is obvious, but by no means easy to achieve.
I have heard of Marcus Aurelius, and am roughly familiar with the Stoics, some of whose philosophy is admirable. However, as a practical matter, I was raised by and around a bunch of dedicated military veterans who also are devout Christians -- double sources of discipline to draw from. I am also a student of U.S. military history, emphasis on the Civil War, and am well aware that I am sitting here free to be typing this because the Union at last found a general with the discipline to stay the course, against all early indications, casualty reports, and the entire of public opinion in 1864, until he defeated his equally disciplined and famous opponent in April 1865. No one can ever say that Ulysses S. Grant wasn't emotional; there was a time in his life that he used the bottle to help him ... but the day came when he was able to take up a dismayed army and harness not only his emotion but theirs, toward victory. I can't say Grant is a role model, per se, but I note how imperfect, emotional folks learn how to get themselves together and harness what they have!
RE: On the necessity of emotional discipline