Interesting that you say it just started when you did oil change, it does sound like there is no oil in it (obviously is) as stated above do not drive it, DO NOT RUN IT, longer than necessary ( to diagnose) as it can and will cause more damage, Milky white oil is defiantly water in oil so like said, ring mobile mechanic or a tow truck to get it into workshop, As for causes of noise ?? could be a number of things without actually hearing it up close and with a stethoscope hard to say