I've had a bad back for 15 years so I feel your pain, so to speak. As others have said, get your self to a doctor, preferably an orthopedist. If you can, get some muscle relaxants because it sounds like you had a spasm and I've had several and it feels like somebody just shot you. A good relaxant is skelaxin. I'd also recommend an anti inflammatory. I'd say Celebrex but you know that story. The makers of Advil claim that it's just as effective as the prescribed anti inflammatories.
Be careful when you pick up something. Make your legs do the work, not the back. When you're able and under directions from a therapist go to a gym and do exercises that will help you. You can buy a book that has simple back exercises that you can do at home but wait until you see a doctor.
Good luck.