Well, I feel like I invented migraines. I’ve been on every - and I mean EVERY - prophylaxis going with no success but at least it means I can tell you the general process.
GP will want to try you on prolanolol again if it worked before. If it doesn’t work, they might try topiramate. I think GPs can also try you on amitriptyline for migraines (but I can’t remember if they’re licensed for that). If they don’t work, ask for a referral to a neurologist.
S/he may then try you on the prophylaxis that’s unlicensed for migraines - in no particular order, candesartan, gabapentin, Flunarizine. There are also nerve blocks they can try (injections into the base of your skull that makes it feel like the back of your head has dropped off for a day) and localised TENS machines (Cephaly or one that you hold up against your neck whose name escapes me). If none of those work for you, you might ‘win’ cranial Botox. If that fails, some sites are now offering the monoclonal antibody injections. That is actually the one thing I haven’t tried because they’ve only just become available on the NHS - I’m starting on them imminently. Suffice it to say I’ve lost all hope, given I’ve failed on everything listed above, but since migraines make my life an utter misery, I still hope for a miracle.
Less/non-pharmaceutical - cut caffeine completely, eliminate all painkillers for eight weeks including your triptan spray to rule out rebound headaches (yes, just ride out the migraines on nothing...done it many times...awful...), keep a diary to identify any other dietary or behavioural triggers, daith piercing, hot bath with ice pack on the back of the neck, ketogenic diet, magnesium and the MN old chestnut, full sugar Coke with three aspirin at first sign.
I’m sure I’ll remember five other things that have worked wonders for others but have failed for me as soon as I hit post...