2003 Mazda Tribute, I've been having trouble turning it on, after a couple tries it turns on but today?

2003 Mazda Tribute, I've been having trouble turning it on, after a couple tries it turns on but today it stayed accelerated, when I was coming to a stop I had to press the brake all the way down, cause it kept going, then there was like a kickback when I did come to a stop, smoke started coming from the radiator, although there is antifreeze in it. HELP!