1994 Trooper, PLZ HELP!

Ok so I recently purchased a 1994 isuzu trooper, the alternator was just replaced before I bought it. When in drive the car doesnt seem to shift (its an auto), the rpms will go very very high, but wont go past 10 mph. The warning lights ( of every kind ) go start lighting up, and go off after about a minute. All except the transmission light which seems to stay on for a little while longer, before eventually going off also. It seems to drive fine if I shift into Low, 2, and 3. But just recently it wouldnt go at all in drive, the rpms just ran out the roof but no motion. I recently got a tune up and an oil change. Im not sure what to do PLZ HELP ME! Could this be an electrical problem?