Stutter EXPLODES at drive thrus

Stutter EXPLODES at drive thrus Everytime im at a drive thru, I block so bad. I can get out the “Can I get” or “May I have” but when I go to say the order number or meal name I block terribly. I usually make a sound and even jerk my head to get the words out. My stutter is never like this only at drive thrus, it’s like I go mute. This also happens when I’m inside a restaurant. I’ve tried to change the way I order food with different phrases but nothing works. Anyone relate? I’m terrified of going through drive thrus now.