Hi

Did you ever experience this:
I have a full time job for 3 years now. The pay is not too much but OK, and the job was started as "wow, this is suited for me" but now, I don't like to go to work. Every morning I think "oh, I hate this treadmill". I always get depressed on sunday evenings as I need to go to work next morning.
When I started it, the job was pretty diverse. Sometimes I coded programs in the office, sometimes I went to customers to repair or upgrade computers, sometimes I build new networks and so.
But recently I only sit in the office, coding for f*ckin' PDA-s (boy I hate them) and getting depressed as my boss picks on me and always asks for some stupid modification on the program.
Nowadays I can't sleep enough and I'm always tired. It feels like I were a little drung all day. I cannot concentrate on my work.
Recently I have huge mood swings. One time I'm feelin' happy, five minutes later I'm depressed again.
On top of this, I don't have a real girlfriend. There's a girl I used to hang out with, but this isn't love from either side.
My family suggests that I shoul quit my job and search for another but this isn't that easy. I applied for various job offers recently but either I didn't have the necessary papers or I didn't get a response.
Have anyone experiences such a situation? What can I do to get out of this?