@david96,
Welcome to Mayo Clinic Connect.
Wow.
And Wow is an understatement.
I can only imagine how you feel. No wonder you feel fearful and uncertain.
The Mayo Clinic has international partners, but when I checked, there were none close to you. London, UAE, India...
Here is a link to the Mayo Clinic International Department:
https://www.mayoclinic.org/international
You have a reason to be fearful. Septal myectomy is such a specialized procedure, that it should only be done by a skilled surgeon who has done hundreds, if not thousands.
That you still have an obstructions speaks to this. The risk of over correcting this obstruction can be devastating.
You really are in a difficult position.
My hypertrophic heart was breaking when I read your story!
Has your cardiologist suggested Camzyos or Afecatman as an alternative to another septal myectomy?
I'm not a doctor. I can only share my story and advice and ask questions. I just wonder if you were offered drug treatment or if your HOCM was too far advanced.
Were you able to get a second opinion?
The thought of going through another open heart surgery with the risks involved in your case would cause me to research alternatives, second opinions, or third opinions.

I can't imagine how this must make you feel. To be so young and full of life and a new future, and now this colossal diagnosis and failure of treatment.
I would encourage you to contact the Mayo Clinic International department listed in the link above and at least start there. They can give you information about Mayo Clinic services available.
When do you see your doctor again?
How are you feeling after the surgery?