If I was truly in this situation, id hang myself.
Using anything I can find. A tie, bath robe, some sort of cable…anything you can somehow turn into a ligature that you can put around your neck, and that will hold your weight
People in jail use T-shirts, shoe laces etc in jail.
Heck, there's been instances where young kids have bunched together shoe laces/cable wires etc and still managed to hang them self.
If you've got some time, find a cherry field and rob shit tons of cherry's.
Remove, crush and then consume copious amounts of cherry pits. Replicating death by cyanide lol