Anyone have Cluster headaches? What helps?

@clusterheadsurvivor
Also a six year veteran of eCH. Sumitriptan injections effective until heart palps started about a year ago. (Also take Emgality but not sure it makes much difference.) Then, went to the nasal application, and seems to - but not always - do the trick (pain gone in about 30 min.) But of course can only be used twice in 24 hours. (ij the last four weeks I have had 27 episodes, and the monthly formulary UHC limits four inhalers per month. Pain, like everyone I guess, is incredibly intense.
Questions: I hear about using O2 with some success. Anybody else found that to be true? Also contolled breathing techniques. Also reading about external devices - some medically approved, some not. Anybody used one of those?
Seems like I have gone to TMI. But any comments would be appreciated.