Pinched nerve/back injury or Arthritis?

I am a 25 y/o healthy male.  A number of months ago, I was having a light tingling in my feet and hands that started the day after I did a new kind of weight lifting (that I should not have done without learning the proper technique).  I had no back pain or anything of that nature.  Went to a GP who decided it was a pinched nerve from the weight lifting.  The feeling went away after a couple of weeks.

I recenlyt (about a month ago) started feeling an achy pain in my hands, mostly in the knuckle areas but sometimes on the sides, palms or around the wrist.  This all happened a few days to a week after doing a new weight lifting thing (again w/o proper technique) for a couple of weeks.  

The pain seems to mostly be in the top knuckles closes to the fingernails (on both hands).  It is not worse in the morning, nor do I have swelling or redness.  It actually seems to be better in morning.  I have had some lower back pain, most noticabley if I try to lift something even just a little heavy, I can feel a sharp pain in my lower back.

The knuckle/hand aches seem to all but go away after a few days of resting my back, then it seems that I will forget about it on the weekends, lift things, sleep on my sides or other ackward positions, etc. then the hand pain will be back again on Monday or early in the week.

I know you guys are not docs, but I thought you might have suggestions.  Does this sound like just reaggrivation of the pinched nerve?  Can this kinda pain be caused by pinched nerves or other back issues.  

I haven't been to the doc about this new stuff as I am a bit scared.  I am worried it could be something dibilatating like RA.

Any advice, comments, info, etc?