Sleep 😔

It's 12.51am, and I'm already up feeding him. I just don't understand! He was doing so well for about 2 weeks, sleeping from 8.30pm-4.30am. I'm not sure what's Happened now, but he won't sleep longer than 5 hours at a time 😔 and it's affecting me so bad now 😔 he's up every 2-3 hours at night now. How do I change it? He's 14 weeks old. I just need some sleep, and he's sleep pattern is getting worse every night, even if I do a dream feed, he wakes up like 2 hours later 😔 what am I doing so wrong 😡😔