I completely understand hun - I was much the same with my DD, even down to putting her on formula at around 4 months when I went back to work and found my supply dropping rapidly. She also mostly slept through from early on, but I do recall a few unfortunate nights of letting her cry herself to sleep because I was told she'd fall into bad habits otherwise.

This time around, I'm much more confident in just going with what works for us and not bothering with all the book advice etc. Be interesting to see the differences in how it works out....

Try not to feel too bad hun, she's gaining the benefit of your increasing knowledge now just as much as your DS is and you were doing the best you knew at the time.