What’s wrong??

My son is 14 weeks old and the past few days has been NON STOP fussing and crying. He’ll be changed, fed, burped, played with, held and he’s still so fussy. He’s never been a great sleeper but he’s been waking up so much more during the night and hardly sleeping much during the day. And everytime I feed him or put him in his floor seat or lay him down to change his diaper he pushes his legs against the grown and squirms around like he’s uncomfortable. He’s been drooling and sucking on his fists for a few weeks now so maybe teething? or growth spurt? What else could it be? We’re so sleep deprived 😭