Hi,
Sounds to me like it is definately teething.My DD got her first set of molars around 14 months,and they all came through at once and took a long time to come through.She was extremely grumpy,her appetite wasn't very good at all,and her poo was extremely messy and runny.The molars,because they are so big,obviously cause more pain as they come through especially if they come through all at once.I would try with some pain relief 1/2 before her nap,I gave mine a dose of calpol the english equivalent of Tylenol I assume,and this definately helped with her sleep,I also gave her some before she went down at night.She's still got her last set of molars to come through yet,think they might be on their way,she's nearly 2,so probably will be any time now..
Hope this helps..good luck!
Clare