How to overcome fear of annihilation in meditation and why is it not included in list of hindrances to meditation?

Over a period of last few years I have ***almost*** completely eradicated the 'five hindrances ' to meditation. However, sometimes when I am in deep meditation, I feel an intense fear of '**getting annihilated**' and then my mind immediately becomes restless and meditation is broken. As the mind knows that total emptiness will be the end of 'mind' or 'ego' I think the fear springs from that idea. How can I overcome this fear when the meditation is going on? and also, I wonder why 'fear' is not listed as one of the five hindrances to meditation?