Stutter issue

Stutter issue Hello I am 24. I have a stuttering proble. When I am alone, I don't stutter I can speak with myself fluently. And when I am with known people I stutter a bit plus infront of them sometimes I speak some specific word 2 or 3 times, but when I am with stranger like, I am in a restaurant and giving order that time my mind goes black out I can't speak a single word and I feel like I am chocked. When someone ask my name or ask about me anything my palm and sometime whole body start to sweating. In my mind I know how to respond and what to answer their question but I feel like some force stopping me and I can't express myself to them. So guys please help me on this.