Im taking venlafaxine as a preventive & sumatriptan at onset of migraine but it's not helping. tried all sorts of meds incl beta blockers. what next?

Botox?: Not my field, but you sound like you may be a good candidate for Botox injections as an adjunct treatment, if there is a strong muscular component to your migraine pain. You can check for suitability with your Internist or Neurologist.

Change your meds: Am not impressed with Venlafaxine as an effective migraine preventative, and do not use. Sumatriptan works well if taken with the first hour, but not so good later. There are many migraine preventatives that do work, such as Depakote, Topamax, (topiramate) but also, could try Botox. See a headache specialist and get this under control.