Sleep regression?

My baby is 15 weeks and I think we’re going through a regression. He also has reflux but is on meds. He will wake 30 mins after bedtime… After his first stretch/wakeup, he will wake every hour, sleep for 30 mins and wake again, sometimes he’s even having trouble just sleeping in my arms. Is this a regression? Is there anything I can do? I usually rock to sleep and know I need to break that pattern but is he too young for that? Can he learn to fall asleep on his own?