How do you deal with the reality of loneliness?

What I mean is, how do you deal with the logical conclusion that no one can ever truly be relied on and that you can always find yourself alone with no support?

Or do you disagree with this conclusion and think that some people can be relied on and that you can know that you won't end up alone?

And if you are alone, how do you deal with the inherent human yearn for others when you know that you can never truly rely on them?

Edit: To clarify, I am talking about personal relationships and not about professional or paid help.