hi
welcome to health care magic,
the medication u r getting is right for 
vascular headache but u r experiencing 
side effects of the same medication
pulse variations like either 
increased heart rate and low heart rate is due to 
propanolol which belongs to the group of drugs .. 
beta blocker and it can 
also cause variations of blood pressure 
The doctor must have given u this drug to prevent further episodes of 
headache as a prophylactic agent
YOU CAN BENEFIT WITH OTHER DRUGS LIKE 
FLUNARIZINE ,
VALPROATE kindly stop propanolol and consult your physician for a change to flunarizine
Flunarizine is usually started at a dose of 5mg once daily ,later slowly 
increased to 20mg/day ,usually preferred at bed time
hope u find this helpful