Ok, so I'm driving to school this morning. I'm actually going to make it on time for once. And yea, I turn right on to a street and go to shift to second, but its not there. It just grinds and I put it in third. It isn't the first time its ever done that. So, I'm going in third and go to shift to fourth. It does the same thing. That's a new one to me. But, i put it in fifth and kept going. Hoping it was just a strange thing. So then i go to turn left into the Kmart parking lot I cut through and go to downshift to second... The shifter flops up and down, but it won't move side to side. So I park it (convienent I pulled into a parking lot, isn't it?) and get outta the car to see what's wrong. I thought it was a cable (which is a $131 for GM) but both ends were still connected. But yea, I can't do anything then, so i get a ride to school and go back after school.
So after school, I'm playing with the shifter a little and it pops outta gear. Now, it can do 1, 3, and 5 with some force behind it. So I'm thinking its internal transmission, not the cables.
So does anyone have any ideas what it could be? How bad is it to drive it with the transmission the way it is? Where can i get a new transmission or the parts to ebuild this one? Any help is definitely appreciated. Sorry about the long post, I'm frustrated.

gear box? take the shrouds off and inspect....and then if it still does it disconect the cables and try it again...if it moves the way it should with no cables then its the transmision...i definatly dont know nething about this but its just what i would do