I feel sick

This is basically really bad morning sickness. It's where nausea and vomitting are so bad in early pregnancy that it causes dehydration and weight loss. It happens in about 1 in 750, but generally is not terribly severe.

I'm afraid there's nothing I can do

It sorts itself out by 14 weeks, so the main thing is to exclude molar pregnancy and other causes, and manage fluids. That's it, although I imagine it must suck if you have it.

Unless...

Don't miss out that it could be an unusual presentation of a UTI, a thyroid condition or twins. If it persists, you should do a urine dipstick, a TFTs, U+Es (to check for dehydration) and a scan to check for twins. Boom!