How to measure happiness?

[Cavernio]

(Could've put this in the most recent happiness thread, decided not to, its not the same topic as the thread changed into.)

So I'm not talking specifically about psychometrics, but rather, how do we decide for ourselves if we're happy or not, given that at any point in time, our happiness level is always changing? I think most of us decide for ourselves that we've generally been happy, and ergo, generally ARE happy, or the exact opposite. First question I suppose is, does this hold true for you? Do you decide if you're generally happy for a period of time, or do you just take your emotions in stride?

I guess in the old thread I remember someone saying that they're truly happy when they get lost in what they're doing, and I remember responding with something like "But there's mundane tasks I do that I can lose myself in, and that doesn't mean I'm happy."
Why is this true for that person but true for me? Is it because I feel I have to be losing myself in doing something consequential in order for me to be happy while getting lost in something?

My personal experience with happiness, and my search for it, has been an issue ever since I lost my belief in God, which happened as a result of the unignorable fact that just because I loved someone, it doesn't mean that they love me back, which happened when I confessed my crush for someone over ten years ago. Up until then, I'm not sure I ever truly believed that God must exist, but rather that because I felt God's love, God was real. So, up until then, I would often fall asleep happily knowing that I had a purpose in and that God loved me. This was the impetus that caused me to become depressed for years of my life, unless, of course, its all just been iron and B vitamin deficiency, which I'll never know.

In any case, my happiness when believing in God was simple; I had purpose and love, even if I didn't really have a purpose, God had a purpose for me. Now, even if I have a goal in my life, my life still seems pointless. I know there are people out there who can feel strong connections to nature or the universe or whatnot, and it basically sounds like what I experienced, except that I put the concept of God in there as well, but I can't bring myself to feel some mystic connection to the universe either...its all in my head, and although it is amazing that those feelings can even exist, the fact that they don't have to just breaks the spell.

So, onto the topic of the post, regarding how we measure happiness in ourselves, back when I believed in God, I was happy. Even if I had the worst day, I could come home and be at peace because I knew God was there. I might not even think about God 95% of the time, but that 5% of the time was enough for me to call myself happy. And now, even if i work at a menial job that requires me to be busy 10 hours a day, and then for another 4 hours I distract myself with games, TV, sex and whatnot...that half hour a day before I fall asleep when I feel unhappy, is enough for me to feel unhappy overall. I detest the fact that even if I don't mind my job, and I still invariably look forward to my days off (as most people do), and then when they happen, its like I don't enjoy them. Although I suppose I have yet to work anywhere near full-time doing something I truly like...perhaps if I did that, even if I got bored and sad during my time off, I would call myself happy?