Ah, yeah sounds like it went in spectacular fashion. The only little thing I could think of that it may be, would be if the shift linkage came loose, but I doubt thats the case. Might be worth a look though.
Depending on your time frame and wallet, it might be better to have your tranny rebuilt, rather than putting in a new one. A good rebuild should run somewhere around $750, and you'll basically have a new transmission. Otherwise, try to find one in a junkyard and hope it's in good shape. I try to stay away from JY auto transmissions after I spent a week swapping in 4 transmissions before I got one that worked. But if you're low on funds, labor is "free" if you do it yourself.
I got my Jesus on the dashboard, but the Devil's under my hood!