Episodes of screaming

I need some insight. So for the past two weeks my baby boy has been having these episodes in the evening where he will start crying then all of a sudden start screaming at the top of his lungs. Nothing will calm him down, I try all of his favorite things and nothing works. He had his 4 month check up at the beginning of the month and I told the doctor about this and she said it could be his reflux acting up. Well we have been on famotidine for about a week and it hasn’t helped the issue at all. He’s had colic and reflux since shortly after he was born, it started to go away the it just came back with full force vengeance. I absolutely hate seeing my perfect little boy screaming every night and I can’t even do anything to calm him down. Any help would be appreciated.