HaloAnimator,
Your normal map looks just fine. That’s exactly what normal maps are supposed to look like. You don’t need to invert. Just apply the normal map to your model now and you’re done!
Creating normal maps from black and white bump maps is one method of doing it. It’s a lot easier than modeling a high res version of the model - that’s true. But there are some types of detail that you might want in a normal map that are impossible to paint in a bump map. That’s why some people use the “high res/low res model” method.
I like to use both methods together. I create a high res model for the large details in the normal map and also a bump map for the very high frequency details. Then I combine the normal map and the bump map into one normal map.
You can see some examples of this here:
http://www.monitorstudios.com/bcloward/textures_extra.html