Time to crawl under and trace the shift cables. Not shifting could be a broken bracket, a pin out of the shifter itself, so the console around it may help locate the problem, or, check the condition of the clutch slave cylinder, it may be wet from leaking brake fluid, and when air gets into them from leaking, they are pretty difficult if not impossible to shift. See if it shifts with the engine off, and the pedal feels like it only works about an inch from the floor. These are the two possibilities. Back to the cables, if something came loose or apart with the cables, the transmission can simply be in gear, like second, and once the cable tension is loosened as in broken bracket or cable inside the sheathing, the shifter won't move around because the cable tension won't allow the transmission to come out of the one gear. Trans is more than likely fine internally, just stuck in gear until the cable is fixed, or clutch slave cylinder replaced (check the small round cap reservoir with white opaque four ounce container with one black hose running down about where the clutch pedal is, under the hood against the firewall). If this reservoir is low, when air gets into the system it takes about 45 minutes to bleed the thing.
