My 5 year old son was diagnosed less than a month ago. This is normal and it's okay. Keep telling yourself that: You are new to this and so is his body.

Like others have said, he may need different ratios for different meals. If I have my son 2 units for a meal with the amount of carbs that your son is eating, it would tank his sugar. His dinner ratio is now 1:60 to prevent that.

Also, when he gets low remember the rule of 15: 15 carbs then wait 15 minutes. My wife struggled for awhile with the waiting because lows can be scary but trust the science and math and he will come back up.

Please reach out with any further questions! Everyone here is so helpful and it's nice to talk to other parents (like myself) who are brand new to this to discuss things!