Hello everyone on this sunny winter day ?? Could you please tell me wh...

Hello everyone on this sunny winter day ?? Could you please tell me where you get information about how long a child should be awake and how much they should sleep at different ages? Especially up to 3-5 years old, the norms probably change every 1-6 months, right? I'm asking because I'm tired of searching for information on the internet, where it varies, and since 1.2 months we started following advice (I asked about the routine half a year ago) and by 1.5 years we seemed to have established a schedule, he sleeps great, meaning when he was awake for 5-5.5 hours, he slept for 2-2.5 hours. And he started sleeping better at night, sleeps through the day without needing to be woken up. We also stopped night feedings. But now he is 1 year and 7 months old, and for the past two weeks, every other day or so, he starts wandering around at night for 2-4 hours. Drooling a lot, sneezing and coughing from the drool, it's not a cold, the doctor said, I thought maybe it's the teeth affecting his sleep. But even before, when teeth were coming in, we didn't have such long nighttime awakenings. Currently, he's still awake for 5-5.5 hours before his nap and 5.5-6 hours before his night sleep, and he sleeps for 2-2.5 hours during the day. But at night it varies now, the 10-12 hours mentioned online are rare, mostly it's 7-8 hours, rarely 9-10 hours. I don't understand what I'm doing wrong ??? Please advise if you can. I can't afford to consult with sleep consultants due to financial issues ?? I would be very grateful ❤️??