I am so terrified tomorrow will be my best chance to do it but I am so scared of the pain... I don't want it to be painful god I don't want to go but I can't live what have I done to deserve this
I strongly recommend you don't ctb until you're both ready and steady. There is no timeline but the one you have created --and just as you created it, you can change it. Certainly no one here is watching, checking their clock, wondering if you're gone.
Do not be held to anyone's schedule but your own, and always remember that your own schedule is yours to change as you see fit.
Besides, as frightened as you sound --and I get it! dying is scary!-- there's the practical aspect that if your mind is clouded, there's a good chance you'll make a mistake. Maybe that mistake will only get you discovered. Maybe it will make you brain-dead and worse off than you were before. No matter how you look at it, mistakes are not good.
I've tried to ctb several times now, always looking at that day as particularly good for this reason or for that reason --but really, the reasons were all my own inventions, and even as I mourned losing my chance, I was looking ahead and finding other times that would work just as well. Dates come and go, and none of them are so good that another won't follow soon enough.
Don't rush. Don't
be rushed.
Whatever you decide to do, do it thoughtfully, for reasons that are your own, and on a schedule that is your own.