Doubts about my plan (partial hanging)- opinions?

[suicidaljane]

I have researched and planned partial hanging. I have good rope, know how to tie the knots (bowline and nooseknot), have anchor point. I practiced couple times and I got close to passing out with enough pressure, it was almost instantly in seconds, I started seeing black and felt like I was about to faint and very weak. But lately I started having doubts (they seem irational) that it will fail somehow. Like knots would loosen, or rope would break (even though it is quality 12 mm rope with huge weight capacity and Im not even heavy person). Also Im scared my body will stand up (which is in my position very unlikely, because it is sit in air positon, and I know my body will trash and shake to some degree but it seem unlikely and very hard to stand up from it).
PS: I know full supsension would be 100% sure but I dont have good anchor point and there are no woods nearby