Indica strains are generally better suited to treat pain. I would try a few different strains and see what works the best. You may benefit from topical cannabis applied directly to the most painful areas. You can use ointments, sprays, transdermal patches and other preparations. Concentrated cannabis (hash, dabs, wax) provides strong, fast effects, and it gives one the ability to control the effects better than waiting for an edible to take effect.