tranny help?!?!?!?!

I was driving and all of a sudden I heard grinding and my truck would not move.... I noticed that 4th works but thats it... no 1,2,3,5 or reverse... I was told it could be the carrier bearing?? I am thinking the whole tranny needs replaced but if there was something else that could cause it.. i would like to know... I just put ner gear oil in 2 days ago and it has not gave me any problems up until now... there is about 165,000 miles on the tranny....
Thanks for any help you may have......

4th is direct drive so that means that the power goes straight through, no gears. I have a trans for sale in the buysell but I am in bc canada

Yeap i also have a 5 speed trans forsale might be easier just to get one locally though...

I was told by a mechanic that the throw out bearing is out and is keeping it in 4th....???? If so i just need a place and some tools to drop the tranny and fix it.... Being so far from home is the hard part right now..... I wish it was running would be a lot easier to get around and shit.... what you guys think??? I have a trow out bearing go out in my Chevy Luv... and it was a lot different then this is doing... but I am not rulling anything out at this point.....

i cant see 1,2,3,5 all going out at the same time, wish i could help more though

throw out bearing work the clutch, you would ahave all the gears but they would grind bad