Dude...Old people die not knowing what made 'em happy!
Let me summarize your problem for you;
It's really simple... I can think of ideal situations in my head, but getting there is too difficult
Solution: Expect a little less and DO a little more. Be patient!
Its totally natural to doubt yourself when unemployed. Being fired makes that a little harder but the point is the same; IF you are 20 (?) you have a long way to go and this will NOT be the hardest thing you will face. Thats a promise!
I am 38 and the last three months have raised similar emotions in me. I left my job because I'm willing to take risks to improve myself but I was still left with doubts at times 'cause the phone was not ringing off the wall offering me 100k salary jobs.
Perservere my friend! It's worth it! I hung out and now have the gig of my life! My efforts from the past qualified me for a job that normally requires a degree in engineering! You seem intelligent from your posts (arn't you a computer geek??
) Try tomget into something new that teaches you something you don't know already. If I was 20 again and not tied down to the expenses I have now, I'd go back to school and begin at least an associate degree. A degree is not that important...the discipline of putting yourself thru it is!! The work ethic here in the U.S. leaves a lot to be desired sadly
(This is not intended to be a controversial statement...Just an observation having worked as a manager for many years) As a result, It is not difficult to be a shining star! Be prepared to do more than is expected just some of the time and you win!
That is all the material stuff: The times I have felt truly happy to the core in the most healthy ways I know have been...
(Never thought I'd say this...)The recent birth of my son! I haver never had a paternal instinct in my life and BOOM. Hang on for the ride. 
Marrying my wife...I already had a practice run! This is number 2 but she's awesome!

Helping someone else for NO personal gain! Especially those most in need. (Remember the saying; I felt sorry for myself for having old shoes untill I saw a man with no feet!)
Sorry to go on dude...You just sound like you need a bit of the straight stuff. Hang in there. Life is like this...if things are going good, they are about to go bad! If things are going Bad, they are about to go good!! 
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There are 3 types of people in this world;
Those who make things happen,
Those who watch things happen,
And those who wonder What Da hell Happened?!
Ozzy
'87 GT (Ol' Blue)