Originally, my plan was to use helium gas but because of the helium shortage, most tanks contain too much air to be an effective method to do the job. This is particularly true with tanks used for balloons. My plan B is to use nitrogen because pure nitrogen gas is easier to obtain in the US.
The problem with this method is the complicated setup. It takes quite a bit of time to acquire and assemble this method. The cost is another issue. Not only do you need the tank, but you need hoses, a regulator to measure the gas flow and the parts to assemble and attach the hoses to the tank and delivery system. All of this adds up quickly.
Speaking of, to deliver the gas, you will also need to build "exit bag" to deliver the gas to the lungs. The exit bag alone will take at least two hours to source the materials and build from scratch. Some people use a full face mask, as used by divers but that adds even more cost.
The problem here is it's not a guaranteed method of ending your life. Despite the time and cost involved, unless you are meticulous with building your setup, a myriad of things can go wrong.
One problem is, because the survival instinct can kick in and force you to remove the bag (or mask) as CO levels rise, thus making the whole setup pointless.
If you do gain access to the gas, you will need to be meticulous about your setup and your willingness to follow through. If you are determined to use this method, I suggest finding GAS MONKEY's megathread on the specifics of his setup in this forum. He not only lists all of the details and how to acquire and assemble it, but includes photos of the finished product.
Whatever you choose, I hope you find the peace that you seek.
