I smoke maybe a few times a year now, and I generally find it relaxing and fun and it may slightly improve my speech. When I was in high school (like 20 years ago), I was smoking a lot and doing other drugs (like opiods and xanax) and my speech was a mess. It took me awhile to detox from everything and my sleep was terrible during that time but for what it's worth my sleep now is great. Over the years, I've generally found that limiting all of this stuff (caffeine, pot, alcohol) generally helps with my speech. The more conscious and controlled I am, it can control my reaction and I can have a good game plan for speaking. Even if I do stutter, it doesn't impact me as much as it did when I was a kid. I don't know if that helped, good luck!