In our culture, it is a sacrifice to stay home to raise our children. I am constantly reminded of that SACRIFICE. I do much the same as your other responses, buy second hand, stock up on good deals, use coupons, cook from scratch, be mindful of unnecessary outings (cost of gas), drive older cars, almost never eat out or go to the movies, get great hand-me-downs, drink water instead of pop or juice, use a little less laundry soap, use foaming soap dispensers instead of straight soap for washing hands or baby soap, use both sides of paper before tossing it, plan meals ahead, lower you thermostat no more than 5 degrees during the day, have garage sales and buy at garage sales, go to the park or zoo for 'family vacation" instead of going to disney, buy diapers only when you have a coupon, shop CVS for their extra care bucks reward system (you can get things for pennies or even free from thier ECB program), go to www.hillbillyhousewife.com for other good ideas.
I do try to sell things on ebay for extra income. It is minimal but so is the time and effort. I earned about $600 this year selling things that I had around my own house that I was not using or just wanted to get rid of. Most of which were books and coupons.
Let me tell you about the coupon thing - if you are not using formula.... you can sell the formula coupons/checks on ebay and get good money! If you are using formula buy the coupons on ebay!
I had a coupon that was a $9 value for Enfamil. It sold on ebay for $7.52! I came to my mailbox for free and it only cost me .42 cents to mail it - I never even had to leave my house to ship it out.
It is time to get creative and think frugal. Allow your husband bring in the money and you do your best to cut corners in other ways.
Also know that your decision to stay home is the right one. God gave your baby to YOU for a reason. She needs YOU.
I hope this helps. Hang in there and treasure every moment with your little blessing - even the difficult moments.