I wanted to add Jenny, that you have to be in the right place to start this, but I have been slowly beating my depression down with positive things and positive thoughts. Maybe I never really had depression, and maybe I'm just lucky, but I've seen mine slowly ebbing away by kind of going through some stages. I still have setbacks but the number of days I have down days keeps getting less and less.
First, I had to practice thinking nice things about me and about my outcome (and didn't believe them, but kept trying)
Then I practiced putting myself in a few little situations where I got scared but not too scared, and where I had a likelihood of success. For example, I weeded my garden, went to the store, etc. but not all on the same day
I started reaching out to others in slightly socially riskier situations and established my based of support by calling people who loved me or talking things out with friends
I took a little time away and went on vacation with my family
I started getting things in line with my diet (not in terms of calories, but in terms of healthy vitamin-rich foods and fiber; and, I started exercising again.
The biggest thing was I had to practice not getting into the pattern of obsessing over the bad things. LIke one thought "I can't move" going into the next thought "no one likes me" which became "I'm worthless" and "I have no friends" and spiraling down into greater worthlessness and complete bawling and panic. I will say this is only what worked for me, and not a cure-all, but I wanted to share in my situation what has helped me. It's possible none of these did it - it was just that my brain started healing so I could do these things. I don't know. It's possible I'm just OCDish- and it led to a depressive episode that lasted 6 months.
Friendly has a good point about focusing on what you like about your current job - people suggested to me that I find positives about the neighborhood I lived in and hated. For example - 1) my kids were happy and safe there 2) I didn't have to worry my neighbors would ever actually hurt me in any way 3) We have a beautiful home and there are people who don't have a nice living situation. And let me tell you, focusing on the positives in a situation that has you on yoru knees in sadness is not easy!!!!! But if you keep saying it, beating down the negative voice in yoru head - at some point you believe it.
I wish you luck!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!