Well, striving to be happy, relaxed and passionate sounds like a great way to live, and if your speech is better in the process, that's a double win (or quadruple win, whatever). Like you, my speech is best when I'm happy, relaxed, passionate and congruent, so I try to steer my life in those directions. I don't think there's a cure for stuttering, but if dysfluency is an expression of some inner turmoil, and fluency happens when all is well, then how you speak gives a good indication of your inner state, and working towards inner harmony becomes the default path. That's my opinion anyway, though I'm sure many would disagree.