Teething and loss of appetite?

I think my four month old is showing signs of teething but I don't feel anything on her gums. They are hard to the touch but don't look any different than usual. She's usually mild mannered but has become more fussy than usual and is having trouble staying asleep at naptime...she wakes up crying instead of happy and can't fall back, even with me holdng her. She's also drooling everywhere and biting everything she can find. My biggest worry is her appetite (even though she's a chub so she's got some extra padding - lol) She used to take about 30 - 35 oz of formula a day and for the past three or four days has only taken between 20 and 25. Is this normal and what can I do? I give her cold washcloths and teething rings and try to cuddle and distract her but I don't want to give tylenol or oragel unless I know for sure. Also, can I help her appetite or is this something I need not be overly concerned about?