ok I was driving down the street n i shifted into second gear...then moments after the gear popped out n my car came to a complete stopped...after i started it up again it was out of gear but jumping like it was in gear...a few days later after it was towed back to my house it won't go into any gear at all....can anyone please tell me wat this is...? i'm confused bcuz this has never happened to me before...plz help anyone!!!!

fyi: Most of the gears were grinding pretty bad before this happened...