I blocked my ex on social media just for this reason. Practicing "out of sight out of mind" has been very helpful in dealing with all my second guesses. Stop checking the Facebook... Nothing good will come from it.
Things may look peachy from afar but if he's in early recovery then things probably arn't. If he's still using then things definitely arn't. Focus on the direction your life is going now. Not where it may have gone with him.
Nobody puts their miserable pictures on Facebook.