congrats again on your little baby girl…about a year ago i want in your exact shoes as with alot of other on this site…my son i now 11 months old he has CPKU, we went through the same thing you are with the nursing a few feeds a day and it was so hard we never knew how much he was really getting and his levels were allways doing a yo-yo, I soon had to start expressing and giving him the breastmilk in the bottle. It will get better it is true it may take a while, and there will still be those really hard days but what is really important it that your baby is ok and she can grow up to be a healthy, smart, active child, my son is 11 months and doing great developmentally, he is walking and blabbering all over the place.
I am not gonna tell you that the diet gets easier, because i am not really at that point yet, we still have a hard time getting him to eat the right amount of phe and calories but we are doing it. you can do it and hang in there once. And most of all enjoy that little baby…they are soo much fun!!! let me know also if you need help. this site is great and helped me a ton after nate was born.