It has taken many years, but I have finally devised an enchantment that will extend my life.
The ritual of longevity requires colored crystals for each of nature's life-giving elements. A blue-colored crystal for water, a green-colored crystal for vitality, and a bright, orange crystal for light.
I plan to head out to the cave tomorrow morning and enact the ritual.
Just in case there are any problems, I have acquired a means of reversing the enchantment. It will simply require sprinkling a little elemental dust on each crystal and then destroying it.
Just to be safe, I'm going to leave the dust at home. I can always come back and get it if it's needed. Hopefully, that won't be the case.