As I see it there are three meanings to the phrase "This life".

--Number one is "This life" referring to the years an individual lives through and encounters.
Like an object that belongs to that particular person alone.
"This life is crazy and sad..."

Also, it is the way a person lives.

"The drugs have stolen all I hold precious to me, this life is leading me on the road to destruction."

--Number two is "This life" referring to the existance on "This Spiritual Plane".
"This life will soon be over,"
as life is somthing to be completed so you can visit another level.
"This life is for serving our lord, the next life is for basking in the rays of his glory"

--The third is "This life" as a process everyone and everything shares.
It would probably be more sensible to say "Life" rather that "This Life".

When you are talking to someone, or leaving a suicide note it would be appreciated by the living if you would please specify what you mean by "This Life." For that phrase, like life itself, has many different facets. If you would be so kind as to describe, the living could change the shit of the world into somthing positive, and make life better for those who have not given up.

There are those who talk as if they are dead. They leave their notes saying why this life is so fucked up-- unbearable. They do not say why or how. If it is their life that is unbearble, if it is that the binds that hold them to their lord is unbearable, or if it is the burdens of the world are unbearable.
What I mean when I say they are dead means they know there are things that need to be changed but they never do anything. ....mrrrph.. broke my chain of thought here...
--I think sometimes that those who wish they were dead the most, really want to be alive the most.
I personally believe that the process of life is experienced through change.
I believe through experience that changing things for the better is the best way to feel alive.
Think about it, have you ever felt more alive that when you experienced a great change in your life?
Like getting a new boyfriend, or new friends or a brand new car or finally making the choice to live a healthy life. Maybe joining a new religion, or finally following your new years resolution will perk up your life. Maybe you can go to counciling or confide in someone.