Ceyron

I have had Cluster headaches for almost a year straight now will little sign of it stopping. I am on Melatonin (which has brought my headaches down from three a night to one) and oxygen (to help with the pain as it does not actually stop them for me). However, earlier today I had a triggered attack that oxygen did not even touch. This has never happened before and I would like to find out if this is a common occurrence that is just a one off or if is something I should be worried about. I am currently a bit anxious as I will have my normal headache again tonight and I fear that it may not be able to stop it... Thanks in advance.