It can present just like migraine! Yucky, poor wee lamb. I get it so bad (it was awful during pregnancy because your body is basically just a progesterone factory, and that creates softer tissue and ripe conditions for sinus infections.)
Steaming is good, as is sterimar spray. If it gets vv bad then you might need a steroid spray (or even oral antibiotics). It is such a horrid thing, but when I realised it wasn’t actually my teeth that were falling out, it was also kind of a relief.