A/C Help Now!

We have a 2015 jeep Cherokee limited, we have 70.000
miles on it, we made the trip to Indiana yesterday,  we run
the A.C. the whole way, no problems. However in the last
few months every time we turn on the a.c.,  the motor kinda
boggs down, until we get back to normal speed and it quits.
We're from Alabama and when drove all the way to Indiana
with no problems, when we drove downtown about 2 hours
later, the motor starting bogging down and the motor made
a horrible noise and it almost died after we turned the a.c.
on. We suddenly turned the a.c. completely off and it
stopped and the jeep drove perfect. We got to a store to
check the motor and we smelled a burning smell. So what
could this be cause were currently driving home to bama
with no a.c.. and it's 90° and hot!