Starting a job usually can get you going on having some sort of purpose. Problem is, at least in my experience, is actually getting a job. Job searching can really be grueling carpet bombing of resumes that rarely if ever generates any sort of response at all. I had a three month death march of a job search after graduating this year, and still basically ended up in a dead end that has nothing to do with my degree, and my coworkers haven't even got out of high school yet. By about month two I felt like even more useless shit. Really the best advice I can give you is to just set a goal of ten or fifteen resumes a week and just power through it. Unfortunately 90% of job searching is done online, however my current job was gotten by just spending a week cruising the town and asking/applying literally anywhere that had a help wanted sign. Got maybe four responses.
The other end of the spectrum is getting burned out at your job. Unless its something your absolutely passionate about, its probably going to happen eventually. Working a register was fun at first, but now I just feel like some sort of robot. Which means I'm working on sending resumes again, and hopefully leverage the job and experience I have now to get something better or at least different.
Another route is to do some sort of exercise. It can be very hard to set up and build a habit out of it, but at least you'll be improving yourself. I practiced martial arts for a couple years, didn't really make me more fit, but being capable of throwing someone twice my weight over my shoulder must be worth something, right? Kinda wish I didn't leave, really. January might be the worst month to start hitting a gym, though.