Yeah as long as you're exploring, the game throws camping supplies at you so you can rest a bit more than you think. Also resting is how you see a lot of story cutscenes with your party so it's a good idea to rest every once in a while and talk to your party members.

I have the same problem with hoarding items/spells (probably from playing old RPGs where you needed every advantage you could get) but recently I've just forced myself to use them if I need to and it usually works out fine.