I'm in a very similar situation. At this point I've made some peace that my mom and dad would be devastated. I'm 41 years old. They are seniors now. They signed up for this potential when they had me. I just feel awful for my wife. Been together for 15 and are basically great together. I want to die because of endless, endless failures despite my talents, skillset, and ambitions. I've achieved such insane heights and always have it ripped away from me. Either through chance or my own bad decisions at the last second.
I just wish no one loved me. That would allow this to be much easier. I'm not scared of the dying part at all.
Like yourself I occasionally wish for an accident. After being anti motorcycle my entire life... I got my motorcycle license last summer and got my first bike two months ago. Maybe that will kill me.