6month old stopped sleeping through the night. Exhausted

Okay so my son has always been good about sleeping through the night. We would feed him at lets say 10 pm at night and he would sleep until 6 the next morning maybe later. Now he stopped doing it. He eats around 1am and around 4 or 5 am every morning now. Not sure what happened he was on such a good sleeping and eating schedule. We went to the beach a few weeks ago and ever since then he hasn’t been on the same schedule. Maybe it messed him up but I would think it would be back to normal by now. Last night was the first night he slept from 10:40 to 5:07 this morning. We took him to the pool yesterday and he rolled around in his walker a long time before bed so I know he was wore out so I’m guessing that’s why he slept all night. Maybe he’s napping to much or something? Has anyone else experienced this? I even tried increasing his milk and baby food before bed... he isn’t really sleeping good either he tosses and turns and I have to get up to pat his butt back to sleep. I’m a first time mom so I don’t really know what is going on with his schedule.