I worry about this sort of thing, too. Specifically being too afraid to follow through, because I know if I don't, I probably won't try again. Maybe ever. And the resignation of returning to a life I thought I was done with is almost too much for me to bear. I know the kind of person I am, and I don't want to blow up my already shitty life on the off chance I decide to keep living.
Taking the time to plan ahead is scary, but it also prevents you from going through the ups and downs of attempting and pulling away at the last second. That's my inexperienced opinion, because I've never actually attempted before.
Taking that time would give you clarity both on your circumstances and on your reasoning. And, really, what's scarier-- thinking things through ahead of time or facing all that fear all at once the moment you're ready to ctb? I'd argue its the latter, but that's just me.
I'm wishing you well.