First sickness

My 4 month old has a cold she is very congested(been using the nosefrida and that helps with the congestion) coughing and has an ear infection on top of that. She is on an antibiotic I've been giving Tylenol every four hours for her pain and fever but the thing is she refuses to eat she takes a couple sucks and starts screaming as if she's in pain. I'm worried that she's not eating anything, should I call her doctor or any other suggestions? Thanks.