Post Nissen Fundoplication diet/appetite

I am 3 weeks post-op having had a full Nissen Fundoplication. I was put on a strict diet regime of 2 weeks full liquid diet; 2 weeks mashed/pureed food and then I can try tiny lumps but no bread, hard meat etc. I am eating a good range of foods - mostly healthy: veg, fish, dairy, carbs, fruit etc and enjoying yogurt for the first time in almost 4 years. However, I have absolutely no appetite and get full up really quickly. Dinner is usually a side plate portion of which I don't eat it all. I am eating 5/6 times a day but only tiny portions...is this normal?
I am also drinking loads - water, juice, tea and of course peeing a lot as a result; again, is this normal?

Thanks Sharon. I realise the peeing is linked to the fluid intake and also realise my question was badly worded. I meant is the thirst normal (not the peeing). Lol.