All my life I've had the habit of jerking my body when I get stuck. Moving my legs, stepping around, stomping, ect to get the word out. Very similar to what you described. I've definitely tripped on myself and stumbled doing so as well. It's something that I eventually made less obvious over time. The usual techniques usually work, such as stuttering on purpose. You can try substituting the movement with something that moves your body less like rocking back and forth on your tip toes, or squeezing something with your hand or fingers (i like squeezing my ring). I never think the point is to get rid of the stuttering habits, just to get it to a level that's more comfortable for you. I hope any of this helps. As always, you're not alone, keep asking for help if it doesn't work out.