A jumper who survived here,
It is a book of approximately 250 pages, but it will answer some questions starting on page 99. The book is called: The Complete Suicide Manual by Wataru Tsurumi. There are 2 editions, one red and one black, I don't see any differences between them.
In chapter 3 he talks about falls, several examples that will tell you what to do and what not to do. The first thing is to warn you that less than 20 meters and your chances of surviving increase.
Obviously that bridge is not recommended, the trees will cushion you a lot, even a hedge can save you and leave you with only a sprain. Your only option would be to fall like a prisoner of Vlad the Impaler on a trunk or have the branches cause mortal wounds, something unlikely in my opinion.
I jumped from the 7th floor standing up and survived, about 24 meters, nothing stopped me so I estimate that I crashed at 70 km/h, both legs and hip were crushed, I only lost one leg almost completely. My point here is, you have to fall, "well."
I have no physics studies but at bestgore dot fun there is a compilation of a few jumps from the San Francisco bridge that can guide you. I don't know if I can put the link... if it's not possible, let me know.
https://bestgore.fun/w/p3gVmftYngpbLjF12VbrCu
Basically, if nothing stops you in those 20 meters and you don't land on your feet, you will achieve your goal. They do not recommend jumping into the water, because with bad luck, you will drown, which no one wants in these cases.
I can confirm that it doesn't hurt, half my body was shredded and I only felt a tingling sensation. I suppose the brain leaves the signals emitted by the wounds on standby. The book also says it, I have it in Spanish but I don't think you'll have a hard time finding it.
I myself am also considering jumping out of the window (again) but the fear of falling... I can't deal with it. It would be 2 seconds, which many say you don't suffer, but I think about my attempt and I remember that I screamed.
I also want to make sure I land well, and I'm unable to stand on my head and let go. My best bet would be to sit on the window sill, on my back, and let myself fall backwards in an "L" shape or lean very far so that gravity would direct me downwards head first. All this with their eyes closed, because they say that a high percentage of suicides are killed by a heart attack when they see the ground approaching... curious to say the least.
I was looking into doing ctb with full suspension, but I think I am incapable of waiting more than 10 seconds to pass out, and the pain before that, instead with the fall, would be 2 seconds and only the mental "pain" of not knowing how will I fall At night, straight to the cement and with no option for a doctor to treat me like what happened the first time... If it's not going to hurt and I don't die instantly, the blood loss will do the rest, or so I want to believe.
Anyway, I hope I have helped you at some point, although I may have also put you off for a while hehehe, I'm sorry, I just want people to fulfill their desire the way they want. I'm going to look for other threads on the subject, see if I can get help with how to launch.