transmission won't go into gear..

I was getting onto the freeway and my car
was in the middle of shifting gears and
seemed like it just went into neutral and
won't go back into any gear now not even
reverse. But it still has park only park and
neutral so it seems. Now my car is stuck in
can't move it unless it's pushed or towed.
WTF happened to my car. Car starts idles
check engine light turns on and stays on as
long as car is running sounds fine but when
I move shifter into gear nothing happens but
neutral. Please help.......