This is what you get if you do not make it an ironclad habit to lift with the right form.
If I'd be in your situation I would seek the help of a doctor specializing in Applied Kinesiology and a good massage therapist.
I had a chronic back problem and have wasted much time and lots of money on several doctors--orthopedists, sports injury specialists, and chiropractors too.
Then I chanced upon a chiropractor who was a certified Applied Kinesiology specialist and in three visits my back was normal. I have described this experience in Stadion News of Spring 1995 (downloadable at http://www.stretching.info/freebies.html
Whenever I have a muscle injury I go to a physician who specializes in Applied Kinesiology or to a massage therapist who uses techniques of Applied Kinesiology.
Applied Kinesiology tests reveal the exact extent of damage (muscle or ligament, or both? partial tear or complete?) the specific exercises and manipulations that restore the fullest possible function and even the foods and supplements that speed up the healing of a given injury. For example, a broth made of beef bones provides nutrients that help heal sprained ligaments. (But your body's needs may be different and are best revealed by AK tests.)
In addition to Applied Kinesiology diagnosis and treatment, deep tissue massage helps with healing and restoring function. You can read about massage and how to find the right massage therapist in the Summer 2003 issue of Stadion News.
Do not despair. Follow my advice at the beginning of the Q and A on Injuries ( http://www.stretching.info/question_injuries.html
) and find the right help.