There is no best option available other than gita on all life problem. Its said gita for emotional pain to loss of people either naturally or accident Baghavad Gita Chapter 2 sloka 11-13
अशोच्यानन्वशोचस्त्वं प्रज्ञावादांश्च भाषसे |
गतासूनगतासूंश्च नानुशोचन्ति पण्डिता: || 11||
śhrī bhagavān uvācha
aśhochyān-anvaśhochas-tvaṁ prajñā-vādānśh cha bhāṣhase
gatāsūn-agatāsūnśh-cha nānuśhochanti paṇḍitāḥ
The Supreme Lord said: While you speak words of wisdom, you are mourning for that which is not worthy of grief. The wise lament neither for the living nor for the dead.
न त्वेवाहं जातु नासं न त्वं नेमे जनाधिपा |
न चैव न भविष्याम: सर्वे वयमत: परम् || 12||
na tvevāhaṁ jātu nāsaṁ na tvaṁ neme janādhipāḥ
na chaiva na bhaviṣhyāmaḥ sarve vayamataḥ param
Never was there a time when I did not exist, nor you, nor all these kings; nor in the future shall any of us cease to be.
देहिनोऽस्मिन्यथा देहे कौमारं यौवनं जरा |
तथा देहान्तरप्राप्तिर्धीरस्तत्र न मुह्यति || 13||
dehino ’smin yathā dehe kaumāraṁ yauvanaṁ jarā
tathā dehāntara-prāptir dhīras tatra na muhyati
Just as the embodied soul continuously passes from childhood to youth to old age, similarly, at the time of death, the soul passes into another body. The wise are not deluded by this.
Sage Vyasa stated the below for bootha or prethatma nivirthi/extricate the ghost.
If in case of accident do bhagavatha saptha in home for 7 days so that departed soul should safely travel to next life or plane.
For physical pain sincere faith and devotion in lord Narayana and chanting Narayana 8 letter mantra would resolve.
The mere mention of Lord Vishnu can get rid of all our ailments. There is great power and healing conveyed to those who remember the Lord’s name with faith and devotion. Such is the strength conveyed in the following shloka which is found in the concluding verse of the Vishnu Sahastranaam (thousand names of Vishnu):
ArtA viShaNNAH shithilAshcha bhItA,
ghoreShu vyAghrAdiShu vartamAnAH
vimuktaduHkhAH sukhino bhavantu
आर्ता विषण्णाः शिथिलाश्च भीता,
घोरेषु व्याघ्रादिषु वर्तमानाः
विमुक्तदुःखाः सुखिनो भवन्तु
In case of incurable disease such as cancer.. do ekadashi Vrata (Fasting on 11th day of 2 cycles of moon) Chant Vishnu Sharanama with great faith and devotion have cured cancer. But its on in the end Person bakthi. Sometimes in terminal cancer even death is solution but it can be made painless by faith and devotion to lord Narayana by chanting vishnusharanama.