To disappear or to get rid of fear, Narshimadev Ugram viram stotram.Ugram viram mahavishnu ugram viram maha-vishnum jvalantam sarvato mukham nrisimham bhishanam bhadram mrityur mrityum namamy aham 108 times a day. Or you can recite Gajendra moksha stotram from Shrimad bhagwatam once every day. उग्रवीरं महाविष्णुं ज्वलन्तं सर्वतोमुखम्। नृसिंहं भीषणं भद्रं मृत्युमृत्युं नमाम्यहम् ॥ In narasimha upanishad we can find this gr8 mantra called as narasimha anushtup mantra raj.. also the description of Lord's sudarshana chakra is also given... the great disc of Lord grants liberation freedom from fear etc... the upanishad also mentions the mantra of devi lakshmi Fifth Upanishad Devas approached Brahma and requested him, “Bhagawan, please tell us about the famous Chakra called Maha Chakra. The sages tell that ”It is supposed to fulfill all the wishes and is the gateway to salvation”. Lord Brahma told them: “Sudharshana (the holy wheel of Lord Vishnu) is that great Chakra. On its middle is written, the Taraka mantra (OM) and also the single letter of Narasimha (Kshroum), on its six petals of the Sudarshana six letters (Sahasrara Hum Phat) are written, on its eight petals the eight letters (Om Namo Narayanaya) are written, on its twelve petals is written the twelve holy letters (Om Namo Vasudevaya), on its sixteen petals, the mathruka (model) sixteen letters with their roots (Am Aam, Em, EEm…. Aha) is written and on its 32 petals are written the letters of the “Narasimha Anushtup Mantra Raja.” This is the Sudarshana Chakra, This fulfills all ones wishes and is the gateway of salvation. It is a form of Yajur Veda, Rig Veda, Sama Veda, Brahmam and Amrutha (nectar). The one who daily chants this “Narasimha Anushtup Mantra Raja“ would be able to control fire, control wind, control Sun, control moon, control water, control all devas, control all planets and control poison.