Looks to me like you're headed in the right direction. Maybe wit a bit of shading, it will come together for you. I, personally, am terrible when it comes to shading, so I can't offer much advice, but I am sure there are others here that can help. You might also check out the tutorials section, particularly tutorials for mountains as they might be helpful when it come to shading. Most importantly, don't get discouraged, you've made some fine progress so far, and as you keep working at it, you'll find that it will start coming to you quicker and "easier" over time.