Something to help with reflux at night

My son is 3 1/2 months old. He won’t sleep flat because it makes his reflux so much worse. A wedge won’t help either because he wiggles around in his sleep if he’s laying on a flat surface. When he was a newborn he would end up at the side closest to the bed of his bedside bassinet. I’d wake up and he’d be like 2 inches away from the bed and I’d have to scoot him back to where he started. I feel like a crib wedge would just make that worse. He is already on acid reflux meds. He takes 2.5 MG once a day of Prilosec.