Ear infection?

So today my 2 month old has been crying more than normal. She’ll be happy and then all of a sudden out of know where she starts crying, what sounds to me like a painful cry, she’s been eating less I have fed her 3 times since 6am and she’s not feeding as much only like 5 mins and then she’s done. And will sleep only if she’s in her swing, swinging or in her bouncer while I bounce her as soon as the movement stops she wakes up. Could this be an ear infection?