Feel like idk what im doing.

My son is 2 weeks and 3 days old. He was 7 lbs 13 oz at birth and dropped to 7 lbs 7 oz at his 1st ped. Appointment. They told us then that he needed to be eating 2-3 oz of formuka every 2-3 hours and that we shouldnt need to increase for a bit. Well i changed his pediatrician bcuz that one sucked, and his 2 week app. Isnt til friday but he is acting hungry constantly. He spits up a lot, and we have limited him to 3 oz every 2 hours, which he usually eats all of or at least 2.75 oz every 2 hrs. I dont want to overfeed him or underfeed him. Im calling his dr tomorrow bcuz i have 1000 questions i need answered and ill find out then what is best for him but I feel like such a shitty mom. Its like I have no instinct whatsoever and i cant tell if hes actually hungry or bored bcuz he acts like hes starving all the time. I have ppd so im harder on myself than usual. I just want to take good care of him and him to be healthy. How much should he be eating? Anyone else gone thru this? There has to be a light at the end of the tunnel 🙁