The first thing I'd suggest is to lay off the smudge tool.
In order to duplicate something similar to your real media like the examples you showed you're going to want to play with your brushes. I would recommend experimenting with hard edged brushes with different opacities.
Also sampling colors from your image can go a long way to getting them to blend together, here's an example where I sampled off of your current drawing. I don't know if that's any closer to what you're wanting, but to mix the colors together I did flat colors, and then took samples from your existing shading and backgrounds and painted ontop of the flat colors with low opacity brushes.
You can also edit your brushes to get different textures, or play with the layer settings to get different looks. I hope that helps some (and sorry if my example isn't of the best quality, I understand the tools, but I'm not necessarily a good artist unfortunately)
Edit: I'd also recommend looking up references of water, water flowing off things, islands, and moons. What was said earlier about how you're using short hands is true. They're fine in certain situations, but they are clashing for this image in particular. You can still make all these things abstract without using short hand/symbols