That is precisely what happened to me on my '96 GV. I went to remove the half of the axle that was in the transmission, and no matter how easy any one said it should be, it simply would not come out.
I eneded up dropping the transmission out myself and taking it to a shop for repair. They had to dissasemble the differential, use heat, and hammer out the axle stub. The complete rebuild was $1100. I know the shaft was weakend already (the diameter of the shaft was reduced from rust around the balancer), but I believe a seized bearing let to the total failure.
Now that I've scared you enough, try replacing it. If you can change it and it drives fine after, then you're good to go. If not, you still need a new axle so you're not out anything by trying.
If you dig back there is a really good thread by Rick99 about removing the transmission if you need it, it helped me.
I found on my van though, that I did not have to disconnect the steering at all to get the shafts in and out, just unbolt the lower ball joint and swing the hub out of the way.