I think you forgot to attach the photo of the tree..
Reading these threads will help you:

Thread 'Trees to use for hanging - from a tree expert'
This thread is ONLY for those who 1) must do partial/full suspension hanging, and 2) can only resort to using a tree. I was a professional tree climber and trimmer for 5 years, i trimmed/felled trees away from powerlines all over Wyoming, Utah and Idaho. Just thought id give my best insights...
sanctioned-suicide.net

'How to locate the carotid arteries?'
It seems to be said that I should be able to feel a pulse where they are but I can't feel anything . Any tips ?
sanctioned-suicide.net

Thread 'Do you need to find the sweet spot with full hanging?'
Do you need to find the sweet spot with full hanging? How reliable is it? How long does it take to get unconscious? How painful is it? How does it feel like while hanged? What is the difference between full hanging and partial hanging? Is there any resources here on this site regarding this...
sanctioned-suicide.net
For the ligature (neck), I recommend the noose knot with stopper knot, it slides easily and adjusts itself when applying weight:
Keep in mind to always be alone, so that there is no possibility of anyone lurking around the area..
The best ropes to use are made of polyester or polypropylene, they are strong. Check the breaking load before purchasing. Between 10 and 14 mm will be fine, almost the thickness of a finger.
Remember to also test the strength of your anchor point, so that it can withstand your weight.