BASILAR ARTERT STENOSIS

hi there, i am a 25yr old woman,  i recently took ill with a very sore head, and weakness down my left hand side.  i collapsed three times and was takin to hospital.  when i was there they put it down to a migraine, but this was lasting for days. i was in hospital for four days after have'n an CT they told me i was fine but i was still unwell, so they did an MRI and noticed that there was a blocked artery at the back of my head.  then i saw a neurologist who sent me for a CT Angiogram.  this told the doctors that my BASILAR ARTERY was 60% blocked.  i was put on asprin and simvastatin and then sent home to be reviewed by neurology.  It has been 5 weeks now and i still do not feel well at all, i am so tired and i still have a very sore head.  

could you please tell me if this is serious?

would they have to operate??

my own GP does not seem to know alot about this artery and all i want is some piece of mind that i am not going to drop dead from this any time soon.

thank u

debbie