I can't drink water please help

I've been suffering from Gerd for the last 12 months. I'm on a very strict diet, I take probiotics two times a day.
However, i still feel nauseous and my throat is tight. I already had an gastroscopy done. I was prescribed Omeprazol, but after taking it I felt so much nausea that I ended up sitting next to a bucket for an entire day. So I'm scared to try it once more.
But my symptoms are awful, I can barely drink one glass of water a day. I always feel "too hydrated", and if I take a sip I almost throw up. I'm only 17, and I think that I might just die because of this. This life is hell.
So i'm asking for help, does anyone have any ideas?