Screaming baby

My usually very happy baby (just turned 3 months) has been screaming for no reason. She just screamed for almost an hour and a half and nothing I did calmed her. I tried everything that typically works and nothing. Finally after over an hour and a migraine I put her in the bedroom and let her cry it out for the first time. She finally fell asleep, but now I just feel like a bad mommy. I want to go pick her up and snuggle her, but I don't dare disturb her! Is this her growth spurt? How long will this stuff last? I just want my sweet little girl back... 😩