what is causing this???

My lil boy had his 2 month shots 3 days ago, and the past 2 days he hasn’t been sleeping good (during day) normally he sleeps during the day and now he only sleeps for like an hr and wakes back up, he has been extremely hungry like as if he could eat every hour, he fights his sleep, crying for no reason, being fussy as if he isn’t comfortable but once he does fall asleep he doesn’t sleep long it’s only for an hr… does anyone know what this could be?! I’m not getting any sleep myself but only an hr 😔