I hope its your linkage......Is yours a manual????? I know it might be a stupid question, but i have know some people who drop it into second in a ATX car...(stupid stupid

IMHO) But back to you....Im tkaing it you havea Manual....The exact way you discribed is how i blew my Diff....cost me 1300 to fix (no warrenty)and do a major rebuild of the tranny. your should be still cover by warrenty, but what you described....
3 main things that could have happened.
1) diff busted...leaving you stranded with no gears.
2) theres a shifter linkage Bolt (Correct me if i ahve the termonology wrong) that can come lose with hard, spirited, or emergency driving...the bolt drops in and can lodge (or dislodge) your sincros and its a complet mess.
3) your shifter cable just snapped.
the first 2 cannot be fixed with out an R&R of the transmission. Also, i reconmend getting a torsen or a Quaife differential....they are the best to be used with our cars. Quaife also comes with a life time warrenty for racing and street driving.
The third one i reconmend using the Focus shifter tower with the Focus cables and ball-ends. It is a lot stronger and it seems to shif easier with these.
But honestly, unless your mechanicaly inclinde or are experienced with transmissions in general, you may have to take it to the shop to get it diagnosed.
Roz