Well, obviously if you're really bad off you should really talk to a professional, but as long as you're not contemplating any ugly irreversible acts, here's something that might help.
Think of someone you know that seems pretty happy about life. How would you describe their attitude? Are they kidding themselves? Are they ignoring the ugly truth about life that's right in front of their eyes and pretending that some happy fantasy world that exists only in their heads is real? Well, guess what. That is exactly how every happy person in the world acts. And the really strange thing is that it's OK. Because the reason that you are unhappy is that you have constructed a fantasy world just as complete and just as removed from the "facts" as the Pollyanna imaginings that you so despise in those happy people.
Reality is in fact neither good nor bad, it is a very plastic inkblot sort of thing that can be bent and twisted in many directions depending on your beliefs. WHAT! you say? What about THE TRUTH? Well, that's a complicated question and it gets into the meaning of life bit that we haven't gotten to yet, but suffice it to say that what is REALLY going on is so strange, so complex, and so far beyond our everyday understanding, that it bears no relationship to what you think of as "reality", "truth", or "reason". Good and bad, happy and sad, these are notions that you are imposing on the world around you. But, more on that in part II of the Meaning of Life Page.
The answer to unhappiness is both liberating and infuriating, but here it is. Happiness doesn't depend on anything that has or has not happened in the past, nor does it depend on your future prospects (thank God, eh?). The simple fact is, in order to be happy:
You Must Decide to be Happy.
Yep. Isn't that aggravating? You can't blame it on anyone else, and no one else can do a thing for you. You've just got to decide to be happy, whether or not your logical mind thinks it is rational to be happy and whether or not your moral sense thinks you deserve to be happy. You absolutely will not be happy for any length of time until you decide to, and if you decide to, you can be happy in the face of the most miserable circumstances.