I'd do these things first:
>make one last backup of my data
>overwrite the headers of my encrypted drives except for one backup drive
>hide that backup drive
>factory reset my phone
>write a succinct note to my mom
>pack gun, some food and a drink or 2 into a bag and head to a secluded area
>once there, eat, drink, and relax a little
Then I'll kill myself with the gun.