Like BW said, it wont make you drowsy, but it can calm you, or obviously, if in pain, take it away. When ive been emotionally upset or something, ive taken a couple panadol and it does help to calm you down a little.
At that age, i would say it is most probably teething. I tend to give panadol before i give nurophen though as you have to make sure theyve eaten with nurophen.
Hopefully if it is a tooth, that it comes through soon for you.