There is just so much wrong with just about everything shared I wouldn’t know where to start.
Grab and break down the community ocean project to learn how things should be done. Then revisit what you have with that knowledge.
You aren’t too far, all things considered. So its likely worth your time.
However none of this is a fuild simulation. This is just basic water sheet interaction done with a render target. Nothing fancy.
Also… since the origin of this Fluid Ninja came out - many people find that it provides much better fluid/smoke simulations than they are capable of making calculations for.
It could be worth someone’s time to check it out and see what pitfalls it brings to the project/rendering etc.