Why do they call me mentally ill

So 23(m) I want to off myself ,actually no I am going to off myself soon I have a date picked out and all . Just right now completely a stupid bucket List I can barely afford .But why do people call me mentally ill when I say am depressed,anti social and am offing myself .like can’t they see that if they were in my shoes they would do the same . Can’t they see it’s logical a very good choice ?