Passion?

I've read so many articles about jobs and how to find your "dream job", that job that embraces your true passion. But how do you find that passion? I've read things about this, but I can never come up with anything for myself. I'm afraid that I won't like something in 6 months and will have to start over. I truly have no idea what makes me tick....what makes me want to get up in the morning and go, go, go! Part of this could be that I feel very dejected as far as the job market goes. It seems that I qualify for nearly nothing and am over-qualified for nearly everything. I've done so many different types of jobs and yet none of them were great. I never woke up and really wanted to go in to the office. Currently I work in retail to get some income to keep Jason and I half-way afloat, but it's something that I don't love. It's stressful, since I'm in a commission-only position. It's also hard working around others that are 10 years younger than me making more money than I am with a degree and a master's degree. Does that make me sound full of myself? I hope it doesn't, but that's how I feel. Some days, work is pretty good. Others, it's tough when I know I'm not coming home with much money. It's even tougher knowing that there aren't any more job prospects for Jason and that I am the sole source of income for the time being. It's not a good feeling. But back to the original question at hand....what is my passion? How could I spend so much time in school and still not know where I fit in? It makes no sense at all! How do you figure this out? And how do you find a job that embraces it? I know that the job market is terrible, but I am so freaking tired of hearing about it. What do you do when you were out of a job for 22 months and then took a retail position? Where do you head next? What can I possibly do to change our current situation? I'm seriously out of ideas.