Fear (bhaya) and raga (attachment) are modifications or vrittis in the mind. They are temporary whirlpools or waves. The substance of the mind is nothing but raga and fear. They are twin sisters. Hence they are closely related to each other. If you destroy fear and raga there is neither life nor existence for the mind. The Upanishads declare, 'Detachment, faith, fear raga, shyness, modesty, shame, etc., are only mind'.
Fear is a product of ignorance or avidya. Man forgets his essential, divine nature through maha or infatuation and identification with the body. He was the all-pervading, immortal, fearless Soul or Brahman in the beginning. He was the 'Santam (peaceful), Ajaram (decayless), Amritam (immortal), Abhayam (fearless) Brahman'. On account of egoism he became a rebellious child. He separated himself from his Father. He instigated division 6f property and started his own independent living in this earth-plane. He rented a house in the mundane world. He entered the body-house of flesh and bane and became a little, timid man, a little jiva, with all sorts of fears. Thus started his downfall on account of his quarrel with his Almighty Father, and owing to his starting a new egoistic living with raga-dwesha (like and dislike).
He was bodiless, muscleless, fleshless, boneless, I-less, mine-less, desireless, when he was one with the Father, when there was a joint family, and so he was absolutely fearless, and ever-blissful and peaceful. He had no thought of body, house, property, wife, children, position or prestige. He had no thought of diseases of body and fall from his social status or prestige. He had no thought of enemies, war, riots and of running to any place for safety and security. His original abode was peacefully secure and free from any sort of danger and enemies. It was all one Brahman community. There was no Hindu-Muslim trouble there. There was no fear of attacks through bombs or torpedoes. It was an impregnable, invulnerable fortress. It was disease-proof, bombproof, earthquake-proof.
In his new, independent egoistic life, he became selfish, crooked, narrow, and mean-minded. He entertained low thoughts. He ever thought of flesh and the pleasures of the flesh. He practised the philosophy of flesh which is synonymous with 'Pig-philosophy'. Every day fears multiplied, as he was very much attached to his body, the bodies of wife, children and to his house, property etc. Due to attachment even to a fountain-pen, walking-stick, boot, watch, towel or cloth, Fear slowly creeps in. There is fear of losing them. Always entertain the thought, 'All objects are illusory, perishable and pain-giving'. You will have no attachment. Even if there is attachment, it will be mild. You can drive it away with slight thinking and discrimination.
Lord Krishna says in his Gita, 'Vitaragabhaya-krodhah sthitadheermuniruchyate' - 'He who is free from attachment, fear and anger, is called a sage of stable mind'. Abandon attachment through the practice of non-attachment or vairagya and attachment to the lotus feet of the Lord or fearless Brahman. All fears will vanish!
Abhinivesha or love for earthly life is the main cause of all fears. Abhinivesha is clinging to life and body. Attachment to objects causes fear. Attachment to name and fame causes fear. Attachment to money and woman and fame causes fear. Any attachment is the womb of terrible fear. One who possesses, fears. He does not feat who has renounced everything, who perceives the Atma in all Give up attachment to this body by identifying yourself with the bodiless, sexless, pure, all-pervading immortal Atman or Brahman.
We are afraid because we love certain things. Love is the cause of fear. We do not wish to part with certain things. And when anything obstructs our acquiring those objects of love and desire, WE are annoyed, we are afraid of that, and we lose our mental balance-Renunciation of everything, and cultivating Brahmabhava is the best remedy to overcome all fears.
Sit and introspect. Find out the root of the trouble. If you are not able to do this yourself, get the help of a psychotherapist or a yogi. The thing that is deeply buried in your subconscious mind should be released or dispelled.