HELP!!! jeep transmission slipping?!?!?

[Acer 8]

I have a 1996 jeep grand cherokee lerado 5.2l v8 and im curently on vacation with my family and I need this fixed so I can get home. So my jeep when taking off at about 15 to 20mph seems to shift into 2nd or or 3rd and then instead the rpms jump up without shifting . If I get up to freeway speeds without pushing the jeep it does fine, but if I push on the gas like when im going up hill the rpms jump to like 5000 with very little pull. And when I push the overdrive off button nothing happens. I did the key on off on off on for the obd it is a code 12 which is no output shaft sensor signal on the transmission. Does this sound like the symptoms to a bad sensor on the transmission, or what could this be? There are lots of hills on my way home so I need my jeep to shift not just go to high rpms