Not able to engage gears when running

I have a 74 dart sport with a 360 and a 72 A833. I was driving and it made a weird grinding noise. I was in 4th gear. I slowed down and put it in neutral. After I Parked it I went underneath and saw that the nut for 1/2 gear was loose, I tightened it and it seemed good. I was able to shift from all the gears. I then started my car and it didn't allow me to put it into any gear. I put it in 1st and started it with the clutch pedal to the floor, I got a terrible grinding noise. I then put it in neutral while running pressed the clutch and saw that it didn't disengage the clutch.
Did my pressure plate or clutch just go out or could it be linkage? I'm not familiar with transmissions. If you have any ideas let me know.