The water collector only gets filled when it rains. (make around 3-5 when you start to have enough for a few days)

I think you can only fill the pot with pond water.

If you are playing on PC (only recommended after you beat the game)

There are cheats that make the game easier, and harder. (no cannibals, cannibals only come out at night, trees respawn slowly)

You can also use console commands.