Serious Input Needed

After attempting to seek help on numerous occasions through the use of therapy, medication, and even religion, I’ve decided to pursue that “final exit”. I’ve thought about it, and have decided to definitely go with the helium method, only I won’t incorporate a hood. Instead, I plan on locking myself in the trunk of my car (the idea is to become trapped in a small, closed area, so as to be overpowered by the helium), releasing the helium from the tank inside the trunk, and handcuffing myself in order to prevent any possibility of me waking up later on and attempting to shut off the valve, or open the trunk. I would also take a sleeping aid prior to going inside the trunk to lessen my chances of waking up. Does this particular method sound logical? I would truly appreciate anyone’s input on this.

(I would have loved to try the typical shotgun-to-the-head method; however, due a recent suicide attempt and subsequent involuntary hospitalization, I am now ineligible to obtain a permit for a gun. And, unfortunately, I don’t know anyone from whom I could acquire a gun illegally.)

Thanks in advance…