Hi Mamadeb!
If you have been on the Nortiptyline and Ideral for 6 months and it doesn't seem to be working, then I would check with your doctor about either tweaking your dosage or trying something new.
One potential side effect of Nortiptyline is weight gain.
As far as Botox goes, give it a shot! I would think you would still want to find a preventive medication as well though.
You can find more info about botox in this article: Intradermal Botox for Migraine, Headache, Pain Disorders.
Good Luck!