The surest way I've found to eliminate anything resembling imagination or motivation is to work on getting a Bachelor's degree in Information Technology from an online University. Once you've eliminated those two things then the rest of it won't bother you that much.
If you're persistent about this being creative thing, post some of the maps that you're created. You may well find that other people don't think that those maps are as bad as you think they are. At the very least folks will probably offer suggestions or pointers to tutorials that you might find useful. In short don't give up (I also recommend avoiding the BSIT thing, too...)