Yeah, I can completely understand where your coming from. There's always that subconscious power struggle going on in your mind.
I recently got a job at a Supermarket and working the shelves. I had to snap out of this real quick. Whenever someone had a question, they always come to the guy working the shelves. And just taking orders in general. IT's really not a scary thing dealing with strangers. You dont need to go out of your way to please them or impress them. Dont think too much into the interactions and treat it like you'd treat anyone you were already acquainted with.
Try and work on being in a cheerful, social mood as often as possible. You dont need to make life long friends or find your soul-mate in these interactions and dont stress it and go with the flow. Over time, you'll be more at ease and you'll probably find yourself becoming more charismatic naturally.
The only key is to keep going out and putting yourself out there and getting out of your comfort zone. Even if you get a little uncomfortable and awkward, so what? Dont let things stress you like this and be an easy going guy, everyone wants to hang out with that guy. Try and become that guy
