Engine bogged down, white smoke from tail pipe

this car has had an oil leak for the last year. the problem was i could never find where the oil was going. i was driving the car and it suddenly bogged down and now is firing tons of white smoke out the tailpipe. last i checked that meant it was burning oil. so my thinking is something happened to the head gasket but i'm not to sure. it's still running and i was able to get it home. any ideas?