Hey Fedodika,
First of all, I wanna say you're really brave, that ref is super hard, mainly because of the lens distortion combined with the awkward stuff going on at her shoulders
A lot of points about construction and stuff have been already made here, so I wanna focus on those arms. You should first go and study more similar poses, find what's going on with the clavicles. I know I need to do that too.
Copying the image is not the right thing to do. And also, instead of pushing paint around for hours, stop and as I said, go paint similar poses. Then come back to it.
In terms of values, her skin is a bit too bright, or at least the bright spots are too big, should only have accents like the one you see on her forehead. You missed that, that's a beautiful accent right there. Ball of the nose, same thing, bright accent that goes up the bridge and slowly fades - absolutely beautiful. If the accent is not bright enough, it means your skin tone is too bright, so darken it. If you look at old masters, you'll see a lot of red noses, because they needed the darker value to pop that highlight.
Also, don't be scared to use more color. Meaning really adding more hues, use reds, use greens, yellows, saturation vs desaturation.
Of course, I don't think I need to mention knowing the anatomy and using it to change awkward areas that will otherwise give a weird look to your painting.
So here's how I'd do it. I don't usually go that far, and when I do, I try to simplify stuff a hell of a lot and find lighting setups that help create shadow shapes I can play with.
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Not sure if this helps, but I can tell you this pose was a challenge. Next time, try something less complicated, without being cropped or distorted.