Do you have some more info of what it'* not
I mean have you ruled out anything at this point? How long has this been going on?
If not try to fuel pump/system first, it sounds as if you aren't getting enough fuel pressure at the engine.
I have a 94 SE and my "GM Dirtect" fuel pump quit on me after 11 months. and it did almost the same thing. I would be cruisin along fine and then I would lose power, have a jolt because the car was now pushin the tranny. steppin on the gas did nothin. the car wouldrev a little for 10-30 sec then die and I'd have to park it and start it to get it going.
Hope this has given you some Ideas