If you think you should call 988 for yourself, you probably should. Consider the results of a false positive versus a false negative. I think the people on those lines are happy enough to deal with 100 of the former to prevent one of the latter.

More subjectively, if you find yourself at a moment where you simply cannot think of any reason not to kill yourself, and especially if you have a fairly concrete plan, well, what do you have to lose? You can always apologize later.

Regarding 911, I called once, the real deal. I was appalled and experiencing a fair amount of shame, but realized that all social conventions had fallen away. I had found myself in a pit of agony with no way out, and there was nothing I would not have done to get out. I'm not saying you should wait until that point--many life-threatening situations do not involve agony--but if you're there, you definitely should make the call.

In another case, I called 911 for a child. I thought there was a five percent chance that she would experience an outcome that would terrorize her and maybe destroy her life. Close enough.