2 months old inaayawan ang formula

Baby ko po 2 months old, since birth nagformula n sya ksi CS ako at naconfine sya sa Nicu for 1 week. In short, mix feed po sya ksi parang hindi sapat milk ko, nakaka 3 ounces sya s formula pero since May 16 inaayawan na nya bottle. Worry po ako na papayat sya o baka ano mangyari. Any advice po will be much appreciated. Thank you