I have been meditating for about 25 years.
I do visualization, self hypnosis, tapes, etc, too. But "mantra" meditation helps when *everything* else fails, even meds!
Sometimes I have to take enough pills to dull the pain to mediatate - it is hard to stay still when the pain is really bad. If you need to, try meditating in the bathtub. That is often the only place I am really comfortable. Better have someone handy though so you don't fall asleep.
I meditate a minimum of 1 hour am and 1 hour pm. That is a *lot* though, 20 min 2x a day is the usual "dosage."
I was on fentanyl, vicodin, cymbalta, lyrica, naproxin, and lunesta. But all that sometimes doesn't stop you from trying to squirm out of your body, let you sleep, or even rest.
When I can't find any peace, all I can do is meditate. Sometimes up to 5 hours a day when I was still working.
Teach yourself. There is a good book, easy, called "The Relaxation Response." Buy the older, 1980 version for $5 or so. Go to the chapter on how to meditate.
Or try the local docs, yoga schools, or Zen temple for classes.
Other good tools: Stretching in a shower/bath. Massage. Feldenkrais. Alexander Technique.