Legs, Hands, Eyes, Lips, Head Vibration

Hi,

I am 29 yrs old. i have muscle / nerve vibration more than 5 years. it will suddenly came and gone by itself after 1 or 2 hours. Normally it starts from Knee to feet, the both hands... then slowly go up to my face and head, even i can see my face is vibrating in front of the mirror, the worst is.. my eyes and lips will slowly shrink until difficult to open my eyes and mouth. Then it will slowly go to my entire head. Last time, this kind of vibration only happen when i felt angry. But now, it will suddenly come and gone no matter while i talking to a friend, or driving or watching TV... Not everyday... but it happened maybe once every 2 months or once a month.. it depends...
i went to a clinic and asked for doctor advise. They cant find anything wrong on me... and said lets see if it some serious??? what should i do? thanks a lot