Still struggling...please help

I’m 12 weeks and 3 days now and still constantly throwing up. If I take the zofran I absolutely can’t use the bathroom and it results in horrible physical pain from impaction. The biggest issue is that no matter now little or how often I drink water it makes me throw up so I can essentially only keep down sprite. I’m worried all the sprite is bad for us but I’m also just trying to get through this horrible time. I’ve been like this since 5 weeks. What would you do? Drink the sprite? Force water and throw up anyway? I try to get 2-3 bottles of water in with the sprite but any more and I constantly throw up.