My 3week old girl is always acting like she is starving, even after she is finished eating. I'm not producing enough breast milk, so I've been using 3-4oz similac supplement a couple times a day in between breast milk feedings. Well she was still acting like she was hungry so we tried similac advanced, but I think it's hurting her tummy cuz she has been more fussy and gassy with that. I don't know what to do and I feel like I'm a horrible mom for not being able to feed her enough breast milk.. What do I do?? Is there a different supplement that will satisfy her better?