8 week old has flat spot

Courtney • 👶🏼💙 10/29/16👶🏼💙 6/27/20
My son since birth has favored one side and now he has a bad flat spot on that side. Idk what to do to stop him from laying on it. It's making me really depressed, like I'm not doing something right! :( I'm a ftm and I feel like I'm screwing up already. Will it correct itself?? Does this happen a lot?