5.5 month old awful tummy pains, what helps?

Alexa • Micah Tyler born 08/31/17 💙
I'm going to be switching his pediatrician so I won't have a way to ask for their advice yet and my son screams in pain all night long with what is obviously gas or tummy trouble. He writhes around and changes positions and tightens up. I used to be able to help him by pushing his knees to his tummy or massaging his belly or burping but he doesn't even let me do any of those things anymore. He tightens up and kicks away from me when I try. He is breastfed and I am slowly beginning to try oatmeal with a probiotic with him since he's showing me he's ready for solids. But I just tried it today and this tummy trouble has been going on for weeks, just getting worse each week it seems. I'm at a loss. Any recommendations for things to relieve his tummy? We give him mommy's bliss gripe water at night.