Hi 1sttimemum2b. Sorry to hear you've been having such a tough time with vomiting. I probably can't offer all that much advice from experience. I'm 7 weeks, and had pretty constant nausea, but nothing like what you've had. Definitely eating little and often has helped, but I appreciate that's easier said than done when you can't keep anything down.
Which antisickness tablets have you been given? If you're getting bad acid reflux, you need a stomach protecting tablet, if you're not already on one. I know you can get Nexium which are an over the counter tablet if you can't see your GP at this point. That might actually help the nausea and vomiting.
But I'd say if you're keeping very little fluids down, and feeling symptoms such as dizziness, I would go to A&E, as you could be very dehydrated after all this time.
Hope you're feeling brighter soon.x