A personal anecdote-- I suffered from cluster headaches for about 20 years, starting in high school.
Because of bad emotions and not having much success with traditional psychotherapy and anti-depressants, I started going to primal therapy.
I'm well aware that primal therapy is not considered valid in mainstream psychology. I'm not trying to debate that.
I found my therapy helpful for dealing with my daily emotional swings and negative thoughts and feelings.
Surprisingly, I found that it greatly reduced the number of cluster headaches that I had.
Long story short, I had been suppressing my actual emotions in order to appear okay and not an over-reactive emotional wreck. This was a much deeper and subtle process than "I'm okay"-- it was a subconscious, physio-psychological process involving arresting the subtle motions of my face and neck that normally create expression. This process, which I did often throughout the day, subconsciously, when I thought of something personally painful, would eventually lead up to a cluster headache.
That whole paragraph above is something I figured out on my own, while I was doing the therapy, not something that the therapist presented me with or helped me figure out. But I would not have been able to do it if I had not had a space to enact my emotions, which is what primal therapy is (it's not screaming--or, I should say, not just screaming).
Being in a place where you can actually emote what you are feeling, not just talk about what you feel, is a game-changer when you grew up not being accepted for validated as a child. I can talk about how I feel all I want-- that's what I had to learn to do as a child, going to psychologists. That has no therapeutic or helpful effect for me-- it became just another coping or defense mechanism. I'm completely dissociated from myself when I talk about my feelings. I was never allowed to actually feel.
I still have general physical pain, and get crushing migraines from time to time ( I just started a new medication for that), but thankfully I only have cluster headaches about once every six months. I attribute this entirely to the changes that came about from going to primal therapy.
I know that primal therapy has not been rigorously studied, and is generally considered "debunked" by mainstream psychology. But anyways, it really helped me. I entirely certain that the lessening of cluster headaches to almost gone was not a coincidence, and a result of primal therapy.