As other people are saying, do "practice" and "drills" that involve your confidence and speaking with other people. Calling a store or restaurant and asking simple questions about the items on sale or a new deal; go into a store and ask questions about the merchandise; when buying something, try and push yourself down a certain line of dialogue with the cashier; etc., etc. I personally practiced A TON of mechanics with my speech. And I'm honestly one of the most mechanically articulate people I know.... when I'm practicing... But when in a general speaking situation or a work meeting, all it takes is one unknown variable -- you start worrying about your speech, trying to predict possible lines of dialogue, end up overthinking, and now not only will your mechanical speech practice be meaningless, but even the fluency tricks to get past specific stammers won't work. Talking with strangers and asking questions, and even pseudo-stuttering, have been awesome for me to get a lot more comfortable with my speech. And with google maps to search up stores, all ya gotta do is make a phone call!