Suicide is inherently selfish. It kind of has to be. I don't want to discount what you're saying, and even feeling, but I have reservations about the idea that after this wedding, that suicidal ideation is just going to go from "not in an active suicidal state yet" to full-blown "I'm going to kill myself right now" mode, like that of a light switch. If you're still caring about stuff, that's what you're doing. There's nothing wrong with that, still caring, or having hope. I don't think you just turn that stuff off, though. I think it, kind of, has to die organically, not planned. And I do hear what you're saying about giving consideration. You care. Again, there's nothing wrong with that (unless you're a nihilist).
My viewpoint comes from knowing a couple people pretty well who ctb. One was so far past giving a crap about anything that he didn't even care that his mother would be the one to find him hanging. And she did. He had a great relationship with his mother, yet he reached the point where it just didn't matter to him, even though it was a sure thing that she would be the one to find him. Nothing mattered to him, only escape.