How are you people ever running out of ammo? Use the stick for everything. Bait zombies into grouping up, then kill all 3 or 4 of them in one go. You can bait flies into flying lower and lower once you aggro them and they chase. Just back up and then hit with stick or shoot them. Dogs and rats die in 2 shots from the AR if you shoot the head (yes, where you shoot matters in this game, for some mobs at least.) The spiders I can understand if you got baited into stepping onto the webs without ammo or shooting the spider, but you can just walk back and poke everything with a stick regardless.
I do admit that the stamina system is garbage and serves no purpose except delaying your kills.