Don’t forget about carbon monoxide. It would be much easier and less painful to just get a tent or car and a propane heater. Shooting yourself is way too risky in my opinion.
I’m not going to involve myself any further, because I’m afraid I’d do more harm than good.
One thing I've (personally) found helpful is keeping a bucket list, ordered from least to most dangerous/life-changing. If your job is making you miserable? Quit. Wanted to move to a different country? Get a tattoo? Go skydiving? Smoke DMT? Transition? Go for it! You literally have nothing to lose, relative to suicide.
I don't know your life, but I hope you do what's right for you.
Probably you are just using it as a shorthand for "legalising assisted suicide. I assume you live in a modern western country where the idea of punishing someone for trying to end their live is unthinkable. Sadly there are still countries where they would have punished your friend. Because of this it's better to be aware of the distinction between the terms.