I know this feeling very well, each Friday can be different, but I'd say for most of them, I'm very anxious as to what I'm going to do that weekend. As much as I don't like my working week, I don't look forward to weekends either.
Sometimes I have things planned which can make me feel better, but when I know there is nothing going on that weekend, I'll feel very sad and depressed. But it's such a mixed feeling, sometimes when things have been planned for that weekend, I'll feel like I don't want to do them, or just force myself to be alone. It's frustrating!
When I've nothing planned, it's like a struggle to occupy myself until the weekend has passed and over!