unsettled, grumpy and not sleeping well...

[Sagres]

What you describe is very similar to what DD went through, and it was teeth. I won't say how long it went on because it sounds bad, but it eventually got better once toothy peg no.1 appeared. The good news is that the teeth she has got since then have been much easier than the earlier efforts.

The best thing I found to help her feel comfortable enough to get some sleep was Hylands teething tablets.

[onthefly]

Do you have an amber teething necklace? That helped us.
DS' teeth took on average 3-4 weeks each. Nothing helped an awful lot unfortunately.