Sleep training help!

My boy just turned 6 months this past Saturday and we desperately need to get him sleeping in his own room. He’s slept bedside by me since birth and slept through the night until 4 months. Now he’s up every 2-3 hours to eat ever since I stupidly followed the advice of a fill in pediatrician instead of following my gut. Dad works 2 jobs and none of us are getting a decent sleep. Ever. When baby is in his crib in his room he screams nonstop until I finally cave and go get him. I’m at my wits end and he just got his shots today and he’s sick on top of that...next week is his circumcision....I just flat out need any advice you can give me. I have a grumpy babe and a grumpy husband and we all need a good nights sleep.