Opinions on my potential set up?

[magicdeathbutton]

I want to try Fsh, I'm going to acquire a decently thick rope maybe 12mm, should 8ft be enough? Or more? I will tie it to a railing of a loft bed suspended maybe 12ft off the ground using an arbor knot. I will then use a noose knot for the noose and position it just under my chin padded by some socks. I don't know if it'll work but my executive functioning skills are very low and I don't have the resources to plan something else