As per 'Bhagwat Gita -Chapter Two Verse - 18',
"antavanta ime deha
tasmad yudhyasva bharata" (Bhagwat Gita: Chapter Two verse 18)
"Sri Krishna says: All these bodies pertaining to the indestructible, immeasurable and eternal living entity / Soul are spoken of as perishable; therefore, considering this Soul as indestructible, you should fight, Arjuna."
As per 'Bhagwat Gita -Chapter Two Verse - 22',
"vasamsi jirnani yatha vihaya
navani grhnati naro ’parani
tatha sarirani vihaya jirnany
anyani samyati navani dehi" (Bhagwat Gita: Chapter Two verse 22)
"Sri Krishna says to Arjuna: As a human being puts on new garments, giving up old ones, the soul similarly accepts new material bodies, giving up the old and useless ones."
Our body is like our clothes that we wear on our body & after death these worn out clothes are dropped by the embodied soul . You in essence are a 'Soul' & this 'Soul' of yours shall wear another body ( read, shall wear another pair of clothes) after death. So this eternal Soul which is indestructible, changes its present embodied form for another embodied form, when the physical body perishes.
As per 'Bhagwat Gita-Chapter Two Verse - 20',
"na jayate mriyate va kadacin
nayam bhutva bhavita va na bhuyah
ajo nityah sasvato ’yam purano
na hanyate hanyamane sarire" (Bhagwat Gita: Chapter Two verse 20)
"Sri Krishna says to Arjuna: The soul is never born nor dies at any time. Soul has not come into being, does not come into being, and will not come into being. Soul is unborn, eternal, ever-existing and primeval. Soul is not slain when the body is slain."
Eternal Soul was there always & was there even before this 'World creation'. This Soul is never born nor does it die ever. It is an indestructible substance. So if we have a firm belief that we are that eternal Soul which never dies then we shall also feel to be someone beyond this body & fear of death shall go away from our mind as then we shall know that we have life even after the death. Yes, we all are that immortal Soul & shall never die. Have firm faith in these words & all your fears of death shall go away in thin air.