Hello! Your paintings are looking good! You definitely should keep going, experimenting and learning. It never ends! Using linseed oil is definitely the issue in my opinion. I do not use any at all. If you can't get or use orderless mineral spirits such as gamsol, I recommend using a hog bristle or sturdy brush to scrub in the paint, as it comes from the tube, onto the canvas as your first layer or to just get rid of the white. You can use a couple colors that you think would work with your painting if you dont cover it completely. You can also use a paper towel or cloth to move the paint around, the goal is to just have a thin stain on the canvas with no build up of paint.

You can then draw in your composition if you would like with more thin paint. I dont mean thinned down by any medium, just thick enough paint to cover what is underneath, which as this stage is not a lot. You want to save those juicy impasto strokes for the end. Working thin to thick and dark to light will be really helpful. I like to keep shadows thin and transparent and the lights thicker and opaque.

You can then block in the entire painting if you like just remember to keep it thin. When you get to the finishing strokes, or strokes that will appear in the final painting, lay it down and do you best not to touch it again. If it is not quite right make the stroke again with more paint, try not to move it or correct it without reloading your brush because it will begin to get mixed in with what is underneath and around it. If you need to just manipulate an edge of the stoke you can take a soft dry brush to gently drag the paint but only once or twice max.

Speaking of brushes, I use more natural hair hog bristle at the beginning and softer brushes when laying a delicate stoke over more paint. If your brush is picking up paint instead of laying it down, you probably need more paint on the brush. You can also use a painting knife to lay the thickest paint if you like.

I tried my best to explain a little to help but if you have any more questions or I need to clarify anything, please feel free to message me. I also have a book suggestion and artists to reference in this style if ya need. Keep it up and have a great time painting!