Why does my car idle high in park & stall while iM driving.

My car will start fine but by the time I get to the corner of my street it feels rough. I put it in park & my rpm's go up past 4. I shut it off & then restart the car & its fine again rpm's normal. Sometimes I will have my foot on the gas while driving & the rpm's will go up to 4 & I have 2 let my foot off the gas for the car to catch gear. Then I can drive again. Also when I am driving it will stall on me for no reason. On the road, freeway or wherever. All of a sudden outta no where my lights pop on & I realize the car stalled. Also I have a battery gage & the dial on it sometimes goes haywire & the lil red light comes on. It stops on its own after a while. My check engine light is always on & pretty much has been since I got the car 7 yrs ago.