From memory Flunarizine only seems to occur in two strength doses for MAVers at least. 5mg or at an extreme push 10mg. I understand you already tried and dropped back from the 10mg. From all I have read it tends to work relatively quickly and very effectively and as a lone drug for those that tolerate it. Not sure it mixes that well with others I have also read it can react with some antidepressants and I have a strong feeling alcohol. As it’s not one of the more commonly used drugs for MAV there’s only limited information available to lay people. Two fairly recent posters who take it and may be able to comment are @MissMigraine and @Hecoso otherwise maybe you need to broach the subject with your medical advisors. Perhaps it’s not the best choice for you.
Another maybe more readily accessible though perhaps less palatable alternative might be to check out all the other aspects relating to prevention such as lifestyle changes, for example alcohol intake, sleep regime etc. Could be you have been pushing the boundaries far too far too soon and need to rein well in. I have read many times on here archived posts of people having relapses as a result of having had the audacity to try to ‘get their life back’ despite warnings from neurologists etc telling them they needed to take everything very steadily for a long time after the worst symptoms eased up. Remember the meds are masking the condition. Not curing it. So for a long time it won’t take much by way of overdoing it for a return of symptoms.