2003 Standard Toyota Corolla transmission locking up

this week i was driving my corolla down the road, it bucked a couple of times and that
was it a little while later i noticed the clutch pedal felt a little funny and then going
through an intersection the front tires locked up in 3rd gear, the engine was running
fine but shifting into neutral it wouldnt move. when releasing the clutch it wants to shift
by the rpms going down but wont catch also when you rock the car the engine moves
so i know its the transmission. would it be the clutch or the entire transmission i have
checked the slave cylinder and made sure its working, but i know these models have
had issues with their transmissions in the past my car has 268000kms on it. also i
heard that matrix's transmisssions fit what model would be my transmssion ?

Thanks,