Cracked nipples are not yeast, but both are painful. First let me say that it is OK to switch to bottle. I had this issue with my third child(he is 16 now). They call the yeast THRUSH when it is on baby mouth and nipples; I swear I got it cuz I used the nursing pads, I didnt use them with my first 2 babies! Kept it too moist in bra? So if it is yeast, the baby has in his mouth too. His mouth especially will need treatment.(moist area)
It hurt so bad to nurse. I had to treat nipples and newborn mouth for thrush, involved medicine (NOT MONOSTAT!) applied with qtip to his mouth and breasts must be thoroughly cleaned b4 nursing . Oh I cried so hard when I gave up nursing him! But he took right to the bottle, and as long as you HOLD that baby when he has bottle, it's the same! And more enjoyable that PAIN, and then you can heal up, and maybe nurse the next baby (or not). My milk would hardly let down it hurt so bad.
The pus you are describing is INFECTION. Your health is more important than the breast milk. I dont know why we women feel so heartbroken when we can't nurse, but it is ok. You would look back and say it was fine, I promise.
Lanolin for cracked nipples or BAG BALM (cow udder ointment, they both WORK but also must be thoroughly CLEANSED b4 nursing baby.) But you have more than that now, the cracking may have begun the problem.
Last sugestion: Call yr county health dept, they will know how to find La Leche League, they are often county based, and can help you and it is free. But no more Monostat, ok? That is for your OTHER feminine areas :D
Good luck. Nursing is hard, women need to show each other. If the baby has trouble latching, it can cause cracking. Back in my day, they told us to ROUGH UP OUR NIPPLES b4 the baby came, by this i mean twist them, toughen them. And when they latch on, all the brown part POSSIBLE goes in his mouth, more than you'd think possible. And don't worry if you can't nurse, no one will judge you (except maybe you). WIC can help too, if you are not a wic mom, check it out when you call the county health dept.Good luck!