Possible Transmission problem? At a loss!

Hello, last week I was driving home I noticed my 2003 automatic Ford Focus was not accelerating while going up hill, the RPM gauge was fluctuating wildly, and if i applied to much pressure to the gas pedal the car began to buckle and sounded as if it was slipping gears. On a straight away i could ever so lightly tap the gas and i began to build up speed, on down hill I could get even more speed as long as i didn't give it too much gas. I live 3.5 hours away from the nearest town and I was already more than halfway home so I was able to get it almost home by picking up speed on downhill in order to just manage to get over the next uphill. About 1 km from my home i was unable to get it over a hill, I pulled over and when I stopped all of the lights on my dash lit up. I shut it off, was able to start it normally, and got it back home.

When I try to tun it on it will either start normally or not turn over the engine with the check engine and oil lights turning on. All my fluids are fine and there are no fluid leaks. As I said I live quite a ways from the nearest town and a tow would be very expensive, I would like to fix the problem by myself if possible, i'm just not sure where to start. I have been given advice from low Tranny fluid,  failing transmission, and even a bad batch of fuel if that is even a thing. The only notable thing I can think of is that the car was sitting unused for nearly a month.  Any help much appreciated. Thank you.