Hi freckle. I'm now 20+4 with twins, this is also my first pregnancy. You sound worse than I was, I had awful nausea constantly but never actually vomited (except when brushing my teeth but that didn't really count, cause I experienced that when I took the contraceptive pill)
It took me until week 14 to realise that my nausea was caused by severe indegestion -Google the symptoms, it's exactly the same as morning sickness!!! Who knew!! So I tried Gaviscon and it completely took my symptoms away for about half an hour- but you're only allowed 4 doses a day! That's just 2 hours relief!! I got the GP to prescribe Omeprazole which helped but wasn't the magic cure, I still needed gaviscon.
Be warned, if you've got morning sickness, not indegestion, Gaviscon will give you the most horrendous evil vomiting session ever!
After 12 weeks when I expected the nausea to vanish into thin air, or at the very least hope, I expected it to trail off I was so miserable that it seemed to actually be getting worse! At that point it occurred to me that it was here to stay, and I kind of gave into it, stopped hoping for any relief and believe it or not, at that point I just got on with it, it was hardly any better and I had no more hope but I'd kind of gotten used to it, found a few tricks to help me manage it (eating anything salty for me).
At 18 weeks I started to have some good days, now I seem to have very mild nausea for just an hour or two in the morning - VAST improvement! I don't even bother with the gaviscon any more but I am still taking the Omeprazole. Toast with salty butter from the works canteen is enough to sort me out. I can manage the situation and I'm happy.
If at 9 weeks I'd been told id still have some degree of nausea at 20 weeks I think I'd have been suicidal! But it honestly honestly does get better for most women. Everyone's different, you might have magical relief at 12 weeks, you might not, but you will learn to cope (or at the very least you'll forget what normal is any more and just get on with it!)
Good luck.
P.s. These babies were my last chance IVF. They were very very wanted, but three times in the last 18 weeks I have sat and sobbed thinking that this is not what I thought it was going to be like, I don't like it and had genuine second thoughts and wondered what on earth I'd done by getting pregnant..... It's normal. Don't feel guilty please. X