I'm losing my mind! Hayden has been going through these crying fits for the past 3 days. it started…

I'm losing my mind! Hayden has been going through these crying fits for the past 3 days. it started Monday night, he just screamed for 3 hours straight until he fell asleep. we did everything to calm him down like EVERYTHING and nothing worked. then last night he did it again. and he just started again today. he won't eat, he won't sleep, he won't be swaddled and I brought it up to his doctor and she said not to worry about it. but I am worrying because he won't calm down and is crying for hours non stop! suggestions?!?!