Hi Betty101,
It does take a couple of days for your milk supply to come in - in the first few days your baby only needs the colostrum that comes from your breast.
You could try drinking Jungle Juice - it should give you some energy and help with milk supply. You can drink as much of it as you want

Here is the recipe for it:
1L Boiled water
1L Apple juice
1 Sachet Black current Rehydrate
60ml Schlehen Blackthorn Berry Elixir (can get this at clicks or Dischem)
8-10 drops Rescue Remedy (optional)
It makes 2L and must be consumed within 24 hours
These are all safe to use while breastfeeding
Try and not stress about it as stress can have a negative effect on your milk supply
Good luck