If you need to increase milk supply and aren't just relying on formula alone, can I just say good on you for breastfeeding to begin with. Formula is a quick solution which is not going to give your baby as much nutrition. Every drop of breast milk you can create for your baby is an extra bit of antibodies and immune function that they wouldn't have otherwise had!
If I am worried about increasing a new mother's supply in my practice here are the top three things I recommend:
If you do decide to follow my advice to increase milk supply and you need to use a breast pump, a way of making things easier is to realise that once you've sterilised, if you rinse your pump and store it in the fridge between pumping sessions you won't have to sterilise again until the next day.
Another thing that is helpful for this type of pumping is having your sterilised bottles in the fridge with your pump. The general aim is to use the least amount of bottles without putting warm milk in with cold
Some of the mothers I see are very upset that they can't get much milk out with breast pumping and I want to reassure you that if you are getting out milk after your baby has fed, there is not going to be as much as if you were at work and they hadn't fed. Even if you only get 30mL/1 ounce that is still more than your baby would have had if you hadn't done any pumping.
If you are getting out less than this even if your baby is not feeding, rest assured that you are still providing your baby with antibodies and useful immunity specific to your environment. Even one bottle a week is better than none so if it feels right to you, keep up the good work, but only to a level that is working for you as a family member.
Stress won't help you increase milk supply. If you are finding the whole thing extremely stressful weigh up all your options and see what is best for you. I encourage you to call on all favours for cleaning and cooking from those around you, don't worry about housework if it's not necessary (because really, if your carpet isn't vacuumed for a month, it will still clean up when it is next done!)
Failure to Thrive
Diana West, the author of the book above - The Breastfeeding Mother's Guide to Making More Milk - is an international speaker for breastfeeding conferences. She is spectacularly knowledgable and has been working as a lactation consultant for decades.
If you are having trouble with failure to thrive or low milk supply This is the book for you.
Having a hard copy book rather than an internet page is so much easier to physically market the parts that are relevant to you and make sure you get all the information you need in one place.