8 week old Puppy crate training isnt going so well help!!?

i got him to like the crate, he goes in by himself i give him treats.. he quiet... but when i leave to go upstairs or go outside he goes crazy !!!!! he crys and crys and howls and even smacks himself against the crate.. i know that ur not suppose to take him out if hes crying , but he doesn't stop !!!!!!!! i need help i don't know what to do, im going by time and extending it each time like one day its 10 minutes, next day 15 and then progressing it.