Boils can also be caused by toxins. When a body gets full of toxins (chemical, natural... allergy type stuff), and the body is not able to release it through regular means, ie lymph glands, urinating, etc, oftentimes boils develop as the body's way of releasing the toxins from the body. This may or may not be the cause of yours but if it is, detoxifying your body and using remedies to help your lymph glands work better might help.

Sorry to hear you are in so much pain. I hope you can find relief soon.