2000 Land Rover Discovery 2 not accelerating

When my land rover first turns on(in the morning), the service engine soon light blinks, and will not allow me to accelerate it just kind of rolls. After a minute it will go back to normal. Sometimes it will do it ever time I turn it back on, most the time though its just when I first turn it on;waking up the beast I assumed, but its getting worse. I'm not sure if that has something to do with it having problems getting up hills, its barely making up small hills at 30;which is a problem on the interstate.I'm trying to figure out what these two things mean and how can they be fixed!