Your body doesn't expect air. Expecting something is a function of consciousness. Your body doesn't expect air any more than an engine expects gasoline. So no, that's not my conclusion unless you grossly misuse the word "expect".
You can't change your body's need for oxygen. You can change the way you think.
So all pain is equivalent? Is that what you're saying? Any experience of pain is a rational excuse to kill yourself? I guess if you stub your toe, you may as well end it all, then.
Yes, and your basic point that if it ever seems to you like you'd be better off dead then you should kill yourself, is frankly, outright irresponsible and idiotic. Especially with a disease like depression where one of the symptoms is that things seem more hopeless than they really are. In a community that has lost more than its fair share of members to suicide, this is a stance I really can't comprehend.
You can't change your body's need for oxygen. You can change the way you think.