I'd suggest you seek out a professional fitter; it doesn't have to be where you actually bought the bike. That degree of upper body pain suggests to me that you need a pro to look at you. It may be a simple fix; it might not. I've battled myself with upper body issues on one of my road bikes. I tried to work through it--to the detriment of the nerves in my hands.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher