Painting in progress, got any tips?

I began this painting about two years ago as a basic sketch and an ubleached titanium white background on arches paper. It’s based on this digital piece. I’ve done a decent amount of work on it in the past week but I’m kind of stuck, and am not happy with it so far. My attempts to save it have failed. Any advice or criticisms? I am aware of the mediocre composition, and am a little lost as to what to do for the background. Also the snail shell. I will likely paint that over. Yes.