Haha yeah it's brutal at first. There is a wiki for the game with maps containing spoilers - that really helps.

The trick with rabbits is you watch where they're going and position yourself infront of them, so they come closer and closer, with no sideways movement. Then they're easy to hit with a stone.

They don't yield much meat so you need other sources too. Once you find a revolver (check wiki map) it gets a lot easier because then you hunt wolves instead of them hunting you.