Car is a 2008 Nissan Altima S with the 2.5 automatic CVT
First of all I have codes 725, 826, and 300.
I know 300 is a random misfire and I am replacing engine because it burns a lot of oil, excessive consumption. Car has 313,000.

-Sometimes I get no response in OD and I have to put the car in manual mode to move the car.
-Struggles for power above 60mph
-Sometimes when driving the rpms will go back and forth dropping 500 rpms up and down
-Half of the time it drives and shifts fine
-A lot of times it will jerk back and forth when slowly accelerating
-Sometimes at 40 to 45 it will jerk back and forth severely to violent.

I need to confirm transmission needs to be replaced too.

Thank You