There is a sect of monks that brew beer and once a year for several weeks they live on beer alone. It is not Guiness, but it is something very similar. In fact, as I understand it, it is thicker and darker than Guiness. If I recall correctly, they drinks four or five pints a day and stay very healthy during that time.

They did it for the entire 40 days of lent.

There are several antinausea medicines that will probably work, if you have the patience and continue to try. If the doc's say no alcohol, there is a reason. Please do everything you can to allow the treatment to work for you. It is not easy, I know that from experience , but it does work a lot of the time. Drink lots of water, take it easy, watch happy things on TV, eat what you can.

Sending good thoughts and warm hugs.

And a few Irish prayers, if you don't mind.

And after this bad time, I will buy you a case. I promise.

Yes, it was the Trappist Monks of Germany and they actually did it for 46 days. They created a beer called dopplebock. They originally began brewing beer because of a rule that said that all monasteries had to be self sufficient and not rely on donations so the began brewing and selling beer.
For lent they created dopplebock or double bock which some people say is close to the consistency of bread. There have been other people that have done this for lent as well. They drink four to five pints a day spread out over the day so that they remain functional.
I'd love to know where I could buy some dopplebock around here. I'd really like to try it but most people who do it for lent brew their own.