Let me take a good dump and touch your face [art]

[Chris2Balls [:B]]

You raised a good point, Lexou.
I don't know what kind of person you are Diagolesu, but I'm more of a visual/tactile person: when I draw, I tend to imagine I'm running my fingers along the volumes and masses of my subject to feel its shape, depth and texture.
I think it's up to you to try to find an approach which helps you get closer to observing and drawing what you see, as for now you're more into interpretation (which isn't necessarily a bad thing).

Maybe going for a reference with a lot less distortion and foreshortening would be a better start. Both of those points in the current reference make it more difficult to get the proportions right, and the pose is also quite complex.

Last tip: working in greyscale with a background will make it easier for you to set the lighting and colour for your scene afterwards.