HELP! Transmission Related

I have a '95 Camaro Z28... 6 spd... no major mods
Last night drivin home i went to downshift at a stopsign and could not get the car out of gear... so i had to drive home stuck in 4th.. when i got home, i shut the car off turned it back on and it was shifting fine... took it out today and now itsstuck in 3rd gear and i cant get it out at all... Clutch is new and feels fine, only thing weird i noticed is each time before it sticks in gear it grinds for about a half second... every time i try and pull it out of gear while the car is moving itmakes this nasty grinding noise and vibration... Im not sure if its a problem with the clutch or something internal in the tranny... Let me know if u have any idea