1979 Dodge Powerwagon 100/200

I have about 997,000 km on a rebuilt engine (305, I believe, I can't remember). I got it last year, in october. It ran really good for the first little while when I got it, but then last december, I was driving it around my back yard, and I got stuck, and I went to rock it out, and I was going back and forth (oh, instead of shifting into 1st, I just shited right into 3rd, I dunno if thats bad or not), and I put it into 3rd, and it rolled forward, put it in reverse, and it slowly rolled, then didn't go anywhere. I gave it gas, and it still didn't go. So I left it, cause there was snow up to my door. Then today (march 14th) I got in it, started it up (it started excellent, as it always has), and I could see what I THINK is the driveshaft freewheeling ( I had it in neutral and it was moving very, very, very, slowly), and I can put it in gears without putting the clutch in, but there is still pressure on the clutch and its not depressed (clutch not gone?), And when I put it in gear, the driveshaft looks like its trying to turn, but it's not going anywhere. I checked the rearend fluid, and it seems good. I haven't checked anything else, because of the snow, but its melting here, but I was just wondering if you can help me. Any answers would be great, cause I dont realy wanna take it to a mechanic and pay lotsa money for something I could do myself. Sorry for the long post, but I wanted to make sure I got it all explained.