You should edit your post, using Advanced Settings. In the main editor, theres a paperclip in the top row, use that to Add an Attachment, uploading your map from your PC or from a link elsewhere online. That way a thumbnail is automatically created, yet you can add a much larger map, so we can get a better look, without having to directly post an image file. Use this instead of Insert Image button.
Looks good, except its too small to really get an idea of what you created - I am interested! Give me a bigger map to look at and I'll send you some REP.