Uh oh! Bellowing smoke from tailpipe. :(

[Retroman1969]

Well crap, I got the low oil warning on the dash just after filling up this evening.
Took the half mile home, shut it off and checked the oil level again from the electronic gauge (I can never read that dipstick... Can never tell how much is on it). It read only half full at first, then checked it again after 20 minutes and it read full again.
No leaks.... Started motor and it's blowing tons of white smoke from tailpipe and even a little wet oil dripping from tailpipe.
Sounds like it might be really bad.
Or could it just be the AOS??

Could really use some input here!
Thanks!

PS: I always check the dash gauge every morning and it has always read full until tonight.