The good news is that it's highly unlikely that Cyclobenzaprine (flexeril), a muscle relaxant, is going to interfere with busting. It's always possible that I have this wrong, and others will correct me.
In other news: Cyclobenzaprine--WTF?? I've been here for ten years and read hundreds of posts in which people describe the meds they are taking, and if there have been three other people who have had that prescription, I'd be shocked. I've never seen any research that it helps with CH. Maybe some discomfort can be ascribed to muscle tension, but I seriously doubt that flexeril can address it at that level.
I'm probably being overly cranky late at night, seeing another person with an prescription from an actual so-called medical professional that is highly unlikely to have any value, so don't take me too seriously. Maybe I'm turning into Potter (very inside reference). As one actual medical professional has said here, if you take something for six weeks and you don't know whether it's helping, it isn't. So the jury can be out a couple more weeks.
I'm going to imagine that over the course of 33 long years, you have tried the more conventional CH medications and concluded that they didn't work for you--verapamil, oxygen--or maybe you didn't like the side effects of triptans or prednisone. And since your cycles are relatively infrequent, maybe you don't have reliable sources for those things. One thing I can tell you, particularly regarding oxygen but also with reference to those other things, is that they are all prescribed wrong more often than they are prescribed right, so most people who think they don't work for them probably just weren't doing it right. Also, non-pharma things like the vitamin D3 regiment are hugely effective, but largely unknown outside of CH message boards.
You don't have to respond to all that. Just me "venting," I guess. Busting is a good choice, but it can take time, and it's nice to have some effective abortives or preventives while you're doing it. If you haven't seen the general principles of busting as listed in the blue banner at the top of each page ("New Users - Read Here First "), that'll give you a good starting place. Those same principles are listed at the very end of this file -- https://clusterbusters.org/forums/topic/6213-basic-non-busting-information/ -- along with a bunch of other info, most of which, as a CH veteran, you probably already know.