'05 Jeep Grand Cherokee Limited 135k miles, random electrical issues, what's going on???

I bought the car from a used car dealership (I know, I
know), and a couple months later it's starts having issues.
The car will drive fine and then i cut it off, go to turn it on
within 30 minutes and it will try to turn over, the RPMs get
up however they drop and it doesn't start. Keep trying
over and over and you get a burnt gas smell and the car
just shakes, doesn't even turn over. After you let it cool
(maybe 45 min) it will start up. Sometimes you can cheat
the system and pump the gas pedal and it'll start but it
never smells nice and it'll happen again if you turn it off.
It's even stalled in a busy intersection on me. I've tried
taking it to various mechanics, gotten new Cam shaft,
Crank shaft sensors, etc changed on it and the problem
still persists. Now, my car's new favorite stunt is for all the
gauges to drop, lights cut on, AC off, and then all restart
all while i'm driving and it's quite horrifying. Typically only
happens twice in a drive, and not every drive. I need to
take my car on a road trip towards the end of the summer
and i'm scared i won't be able to go because of these
issues. I'm not much of a car person, however, i am open
for suggestions and questions!