You can be driving and pushing on the gas and you can hear the car reeving and the RPM's are going up as you push the gas petal, but the car will start slowing down. You can stop the car put it in park and turn off and turn back on and will run fine for about 1/4 mile, then do it again.
The car ran great, I love it and handles great.
Have you tried checking your transmission fluid? If it is very low, that would cause the problems you described. Naturally the transmission could be bad too, but check the very basics first. For your sake I hope it is just the fluid.
I should tell you too if you are not already aware of this, that if your transmission fluid is low, especially low enough to cause these types of problems, you can expect to have a bad transmission on your hands if you do not take care of it. For that reason, and of course safety concerns, I would strongly recommend not operating the car before looking into and/or taking care of this.
All the best.