What are some things I can do to stop a cronic migraine?

True Migraine? When people are having trouble with chronic headaches, proper treatment is based on proper diagnosis. The word "migraine" is not the same as "bad headache". If you are having frequent bad headaches, the underlying cause could be your neck, sinus issues, allergies, etc. Get the right treatment for the correct underlying issue so you can get control of your pain.
Better Control. Be sure you have tried preventive meds like snri's such as pamelor, the antiepileptice meds like topamax, (topiramate) depkote, zonergran, and Gabapentin (neurontin). Botox is especially effective at modifying the frequency and severity of almost all kinds of headaches but insurance coverage is variable. Stims are a last ditch effort, very expensive, seldom covered by insurance and limit subsequent mri's.
Stimulator treatment. For some types of migraine there is a treatment utilizing a stimulator which is implanted under your skin which has shown to be very effective in reducing or eliminating migraines. Seek a reputable opinion. This is a treatment that many insurnaces do pay for, but some do not.