PZ, the biggest advice I can offer is to persist. Its good that you don't mind the fussy as if you want to get over this, just keep feeding her, spending time with her, being with her. Its so tough as she will be fussy while your body adjusts but then you'll build your supply back up and she'll settle for you again.

If you are really concerned, you could see your GP as there are some drugs that can boost supply (prescription only) but just keep feeding. You can do it!