Infant feeding amount

Hey mummies! Wondering what's the correct amount and timing an infant should be on. I'm feeding my 23days old baby girl NaN opticpro. She has been waking up hourly these 2-3 days. Previously, she can eat up to 90ml and sleep for 2.5hrs but she will have spit ups very often. So now we change it to 30ml every fed and she can drink up to 60-90ml every hour but separated into every 15mins 30ml. Not sure if this is correct but with this, she seems to have lesser spit ups but lesser sleep too. She became awaken easily and sleep only for short periods and very fussy. Not sure what to do now.