I have never tried the bio feedback route so no hlep there. Hoping the verapamil helps you out. For me, just knowing I have something that'll battle the headache makes them a whole lot easier to face. Wishing you some pain free time and soon.

Joe

I've tried meditation which is akin to biofeedback and though it worked for me when I was 17, it don't no more - not for decades! The CH's progressed way beyond that.
I don't seem to recall anyone mentioning that biofeedback works for them with CH's. But I could be wrong, wait and see who weighs in.

Have you tried Oxygen?  That'd be my first choice over all.
Have you tried the vitamin D3, fish oil and all that posted in "123 days pain free and i think i know why"?  That really seems to be working for a number of us.

If it seems like it's not cluster headaches, and the Doc wants you to do biofeedback, well then in addition to the biofeedback I'd personally go see a skilled massage therapist (I'd actually do that first). Make sure you see one who specializes in neuromuscular therapy (certainly don't go to a spa, you won't get nuthin' but "fluf & buff" massage there!). Call around to several and quiz them on what you're experiencing before you make a choice. Not all massage therapists are as knowledgable as they should be and some are downright kookie (I should know, I am one... not the kookie kind!)
Forget about trying Chiropractic, I found that to be a trigger for me.