Adoi, kahak kahak tu memang common jadi dengan baby pakai formula, especially if the formula doesn't agree with their tummy. Try switching to a gentler formula dulu, a few of us noticed our babies punya kahak berkurang when we changed brands, or maybe dia lactose intolerant so kena try lactose-free ones. Make sure juga suction dia bersih and burp properly after feeding, sebab sometimes trapped air dapat cause that sound jugak. Tapi honestly if the kahak tu terus-terusan atau dia nampak uncomfortable, check with your baby's doctor ya babe, just to be sure tak ada reflux or other issues. You're doing great, single parenting memang challenging but you're on top of it!