Transmission problem.

I got this car 1 year ago and from the start
the transmission slipped just a little. Last
night I stopped at gas station and when I
tried to park or put it in park, it wouldn't go
past reverse. I messed with it and got it
into park. Came out from station and it
wouldn't start but turned over and I knew it
wasn't a battery problem. So, at the same
time the gears are off , meaning that
reverse is now where neutral is supposed
to be. I have to shift one gear to the right
of the gear I actually need. So, I put it in
neutral when I need it to go into reverse.  
So, what if anything, is in the steering
column that would affect the gears and
also affect the car starting?? This morning
the gears are still off but the first 2 errands
I ran the car did start back up but the last
stop at Walgreens the car wouldn't start
again. I kept trying and finally it started. I
am a nervous wreck and need some
answers as to what the problem is and
how expensive it will be to fix?? Thanks in
advance for your help!!