The girls, it's been three months already, the son is not sleeping lik…

The girls, it's been three months already, the son is not sleeping like before, he used to wake up only 2 or 3 times, fed and immediately fell asleep. Now he's tossing and turning all night, barely falls asleep after feeding, wakes up 20 times ? so often started asking for breastfeed, I don't understand. Once in 10 probably feeds during the night, I'm not getting any rest. What's going on?