Great work, but as kren said, you need a more "organic look" to your map.
i also think you need to use more natural "outlines" too.(example below)
So, heres another crude edit of your map.
i tried to show how you can make your map look more natural(less straight lines and angles = more natural imo)
i didnt mess around with the inside of your map, just the outside to quickly show how to give it a more natural look.
keep up the great work, my friend