How can I make myself feel better?

It's been 5 weeks since I started working again after my summer vacation and I've never felt so miserable. When I'm at work, I'm counting the hours until I can go home. I'm tired but I don't want to go to sleep earlier than usual because then I don't have any time for myself at all anymore. I want the weekend to start, but when it starts, I feel just as miserable, only good thing is I don't have to wake up early. Every day I know the day is going to be terrible. I don't feel like doing something fun at all, I feel too tired for that and just not in the mood. I don't really care about my work but I know finding another job won't help because the job itself doesn't seem to be the problem. I just feel so miserable all the time... how can I make myself feel better?