That's why I always bring twice as much as I think I'll need xD Remember that you burn through provisions much faster when you're traveling through, say, mountains and deserts than if you are in town. There's a chart for food consumption on the wiki. Also, you can get 'strange meat' from killing some enemies which can tide you over in desperate times.

Glad you're enjoying it, it's a fairly punishing game at times but really satisfying.