I don't like change

So recently my very best friend transfered from my work to another location. I thought I would be ok because it really isn't that far away and we talk all the time. Boy was I wrong! It's weird that not seeing a good friend multiple times a week can put be down in the dumps. Not only is she gone, but I didn't get the promotion I was hoping for. I mean it's one thing if the girl who got it was more qualified then me, but she's not. Only been in the company for 2 months. Pretty sure I know a lot more than she does!
Because of these 2 things work has really sucked. I don't like this feeling. I'm very obsessive and work is my obsession. I used to love it, now I dread it. I don't want to like the new girl because she took my job and my best friends position. I know that it is not her fault but I'm still very angry.
I haven't been this depressed in months. I'm more depressed now than I was when I broke up with my boyfriend! I just don't know what to do. I want to stay in bed all day and I can't stop eating. Not only am I depressed but I'm angry too. It's taken a lot of will power not to punch my wall.
Ugh. Hopefully tomorrow goes better.