Would it help if you cut the rope short, tied one end to a caribiner and a slipknot on the other, place the noose on your neck, tighten it up by hand then get on bucket or whatever then clip the caribiner to the bar and you're ready to go?
I don't know. You sound too close to the bar for it to be comfy, your almost touching the ground before you start. That would annoy me badly. I'd choose a better location, a tree most likely.
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