Major Clutch Problem do I need to replace?

Today jacked the back to replace fuel lines from the tank.

Once finished, dropped jeep off jacks.

Drove for about 3 miles and when I put the clutch pedal down, I can not take it out of gear.

INfo:

Chevy 350
T-18A Tranmission
Dana 300

I put in a throw out bearing about 2 months ago because when I bought the jeep about three years ago the guy put in a new center force clutch but did not put in a new bearing.

The clutch fork, salve, master looking like they are working fine.

With the key is off and I can go through all the gears so there seems nothing wrong with the tranmission.

Is the clutch bad or is something binding?

Sometimes when I jump off a hill (1 foot), it kind of does the same thing for a few minutes (Seems stuck in gear), but after 10 minutes of driving it starts working again.

Thanks for any info that would help me !!!!