Dear Future Self,
In the light of [life catastrophe (e.g., failure to realize dreams, loss of love, debilitating health concerns)], I would like to assure you that this incident has been duly grieved for in advance since [pre-mortem start date].
Over the course of the last [number of] years, any and all contributing factors, appropriate emotions, and feasible courses of action have been accounted for and analyzed to ensure your convenience at this difficult time. The full report is on file in your head, for your perusal during the subsequent sleepless nights.
Your feedback would be much appreciated. Let me know if I missed any pertinent details
...and we'll figure it out, I guess.
You can't say I didn't try. Or that I didn't tell you so.
An Apprehensive But Slightly More Hopeful Version of You