May I suggest a slight change in your "healing dragons" meditation? I'm a firm believer that our bodies and minds respond more favorably to positive images rather than negative ones. Take the man who healed himself from cancer as an example. If I were in his place, rather than visualizing darkness being taken away by dragons, I would instead visualize the dragons coming into my body and breathing their fire into it in the form of light. I would omit any images of darkness itself and focus on increasing presence of healing light. The mind then, is not dwelling on the absence of darkness (which is a positive image that is still couched in a negative context,) but rather it is dwelling on the building up of healing light. This is an entirely positive image. Same end result without flirting with any negative imagery.
