Tranny or Injector Prob?

Jeep Grand Cherokee Limited, 2000, 97k miles, V8: It all started with my engine light coming on then off again within just a couple of hours. A few days later, in stop and go traffic downtown, my car felt like it was trying to die. (Almost like it was running out of gas) Ever since then, it has been slightly slipping/puttering/jerking. I took it to a transmission place to get it diagnosed. (This is where I start getting the run-around)

I am first told it's not the tranny, but it is an injector prob. The code was a circuit #2 failure. Then, a different mechanic at the same shop told me it WAS my transmission. He gave me a long confusing reason why it was now the transmission. After $2300 of tranny repairs it stilll is doing the same thing! AND, I took it somewhere else to run the code and it spit out the injector problem again. So my question is. Could it have been the injector all along (but because tranny repair is pricier then that's what they told me it was)?

Here are some things that might help you answer my question:
My engine light only came on that once and hasn't been back on. I had a new radiator put in 6 mo ago. I just was told today that my AIR FILTER was MISSING! (This could have been from my oil change after the trans repair). After the transmission work, the injector code came back!-- A different mechanic cleared it and it hasn't come back but the car is still running awful. It is worse in the morning or the first time it is ran for the day.

I am a poor first year law school student who has been taken advantage of over and over again by mechanics! Being a girl, I really need some honest advise as to what could possibly be going on with my Jeep! Please help y'all!