Good to see you posting, venuscat. As long as there's life, there's always another chance.
Things looked awfully grim to me when I quit, too. Now I see that's because I was still trapped in addiction. Of course I was depressed, and of course you are too—it seems that's how pretty much everyone feels when they reach the point of quitting.
And, you know, the age thing is relative. Someone else could look you and feel considerable envy that you're quitting so young.
And it's pretty cool to be turning 50, and know that your best years are ahead of you. They are, you know. You're going to be so grateful you didn't give up.