Welcome to the forum, Jay......glad you spoke up.
I can really relate to what you're saying about being so self-conscious, for sure. I know this seems easy for me to say, but i think you'd be surprised just how little the store help care about how you're playing, or are even aware of it. Believe me, they've seen and heard it all. They've been in the presence of worse, older, shakier, uglier
, and for sure less pleasant players than you......and they really don't care one whit.
With that having been said, i understand that you can't help but still be concerned about what's going on in your own head. Is there a certain song or passage that you are best at, that you always come back to, that you'd feel best about playing in front of people, if you had to? If the answer to that question right now is "no", well, could there be one, in time?
My point is, it gets better.....as you get better. A few months back when i was still pretty early on in my education as a novice fingerstylist, i was quietly playing a noodle or two at our local GC, thinking/hoping i was alone, but when i paused, a gentleman stepped around a corner and into my view and said, "Man, i sure wish i could play like that, and make it sound like that."
Trust me, i am NO great shakes on the guitar, and this man certainly had to be a beginner, or possibly born without hands, to think what i was playing was somehow unreachable or not easily reachable, but.....it was kinda cool to hear him say that, right?! I hadn't been picking for too long, but i'd been making strides, and it was kinda neatly reassuring to be paid a compliment on it, even if it was out of politeness.
I bet you're better than you think you are, and while it's virtually certain that you're not going to play your best when you go in there around people, i'd also bet that you'll get a bit better at it, and more comfortable in that situation, over time and with repetitions......just like practicing makes you better.
Trust me, i GET the selfconsciousness thing. Heck, i don't even like peeing in a bathroom with a mirror. But sometimes it's good to get out of your comfort zone.....and you may find that that's the best way to expand it as well!
Good luck and keep playing,
-js