Re: Meditation trouble
IMHO, due to your description of physical sensations after such a short period of time, I would suggest looking at your posture and spinal alignment and maybe even visiting a chiropractor just to be sure everything is okay.
Next, if you are doing Zazen, instead of being brought back to the real world, just sit an be aware of it without the need to do anything about it. If the mind strays, just gently bring it back.
It takes practice. In fact, IMHO, the practice itself is the goal.