help! sullivan will not eat except out of my boob for a little bit. he sucks on his bottle like a…

help! sullivan will not eat except out of my boob for a little bit. he sucks on his bottle like a pacifier and when I take it away and he's fussy he refuses to take his pacifier. he hasn't slept since maybe 2am after I gave him his bath and either cries or finally decided to take a paci. my grandma said he could have gas built up but idk