everyone in the supermarket doesn't care about if you can speak 'normally' they really don't. what they care about is how you treat the others around you. if someone does have a problem, that's their problem. not yours. i've had people look at me like i was a alien from another planet while i try to talk to them, but i owned the situation and i was pleasant and nice thats all people want. the more you go out of your comfort zone the easy its going get. trust me, you've got this :)