Advice for a new mom

Please do not judge! I just turned 22 and a new mom of a 3 month old.
My question is: would it be safe to give my son rice cereal at 3 months? I know I could ask my pediatrician, but unfortunately where I live, the pediatrician/nurses do not seem to care for their patients… I only ask cause it seems like my son is not satisfied with 4-5 oz right before bed. He used to sleep through the night without a problem and now he’s suddenly waking up. I’m sure it’s normal but I just don’t really know if I should start cereal or not. I can’t feed him 6 oz cause then it would be to much on his stomach, he would puke it right back up. But during the day he will drink anywhere between 3-5 oz with every feeding, meaning the ounces are different every time. Everyone around me said they did it with their babies, but websites are telling me to not start before 4 months. Am I over reacting? Am I being too paranoid?
Please help :pleading_face: