How do you know how much to feed your baby?

She will be 7 weeks old tomorrow. I was giving her 4 oz at every feeding but she has gotten into a period where she will not sleep or take naps and just cries and cries and cannot stay asleep. Someone on a previous post of mine said to feed her more. So i gave her 6 ounces before bed last night and she ate the whole thing and slept through the night like she used to. That just seems like a lot to me and i really dont want to be overfeeding her but how do you even know how much she needs? At her 1 week checkup her doctor said if she seems hungry feed her but i dont know if that sticks when she starts getting older? I made another 6 oz bottle this morning and she ate the whole thing and went right back to sleep. Im just worried about overfeeding her and i dont know what im doing 😩 #FTM