Waking up so early

So my son has been an awful sleeper the whole time. He’s 14m old & waking up at 11 & 3 every night. And he SCREAMS. I just don’t know what to do! Do some babies just grow out of this? When I go in the room he is good at laying back down and going to sleep but if I don’t go in then he just screams. BUT he used to wake at the day at 7am. Literally every day of his life it was 7am. Now it’s been 5:15-5:45. I’ve tried giving a snack before bed. Changing his diaper at the 3am wake up. I have a 3 year old also and she is a great sleeper. Sleeps 8-8 everyday. This is mostly a rant but I’m exhausted ha!