How do you stay positive?

I graduated in fall 2012 with a BA in Communication Studies and can't seem to catch a break in finding a job. I admit I wasn't very aggressive within the first year of graduating and was picky in some way about what kind of job to get. Last year I ended up going to London for 6 months, couldn't find work the first three months but then found a job I enjoyed through an agency. After my 6 months were up I came home but ended up trying to get back to London ASAP because I felt happier there. My second stint in London was a joke, I never should've gone back so quickly as I wasn't prepared. After scrambling to make ends meet and feeling like a failure, I decided to return home permanently. Since coming home I've applied to hundreds of positions, even the crap jobs (since being in London I realized you can't be picky these days and got off my high horse) and finally landed a gig at Target. I haven't started yet but I'm already worried about staying there longer than I should. I basically feel like I have panic attacks daily because I don't know how I will support myself since I still live at home. I feel very depressed and closed off.

I guess to make a long story short, how do you remain positive that you'll find a job you love? Or maybe just how do you be positive in general? I guess I'm just looking for guidance.

Any input is appreciated :)