Not being a jerk here: It sounds like you either have inexperienced hands, are tightening things down way too tight, or both. I would take all of your stuff to a local bike mechanic and have him or her give it a once over and properly install your crank and stem. That will get you headed in the right direction and back on the road.

All of this stuff is learnable, but a majority of us started with a trip to a bike shop.