Short answer: No. Do not take Santhārā/Sallekhanā Pachkhan without the guidance and approval of a qualified Jain ācārya/muni/āryikā/sādhvī. Both Śvetāmbara and Digambara traditions insist on guidance for this vow; for householders it is never meant to be undertaken independently.

About the text you shared:

• The wording you posted resembles a simplified community version. However, there is no single “universal” Pachkhan text for Sallekhanā used across all gacchas/ganas. Exact phrases, order, and procedural details differ between Śvetāmbara (e.g., Bhaktapratyākhyāna, Ingita-maraṇa, Padapopagamana) and Digambara manuals (e.g., Ratnakaraṇḍa-śrāvakācāra guidelines).
• Because phrasing and procedure are tradition-specific, I cannot certify your draft as the 100% authentic text for formal adoption.

What to do if a guru or saṅgh is unavailable:

• For Sallekhanā specifically: wait for direct guidance or at least obtain explicit permission/instructions from your tradition’s guru (in person or remotely). Only the guru confirms eligibility, mental state, medical context, transgressions to be avoided, and the stepwise tapering (bhāva- and kāya-sallekhanā).
• In a sudden end-of-life situation with no possible access, maintain internal renunciation (bhāva), practice pratikramaṇa, kṣamā, and navakāra-japa. But the formal Pachkhan for Sallekhanā should still be given or validated by a competent guide when reachable. Do not proceed as a private act.

Key points to preserve authenticity and ahiṁsā:

• Voluntariness, serenity, and absence of rāga–dveṣa must be verified by the guru.
• No element of escapism, grief, or pressure. Mental health evaluation and family/societal clarity are part of guidance.
• Follow your sect’s approved text, daily disciplines (sāmāyika, svādhyāya), and prohibitions (ātyācāras) exactly as instructed.

For basic orientation on pachkhan/fasting (not a substitute for Sallekhanā guidance):

• Upavās pachkhan timing and manner:
• Example of pachkhan usage around fasts:
• Overview list that includes Santhārā/Sallekhanā among fasts:

Conclusion:

• Your intention is noble, but a Sallekhanā Pachkhan must be tradition-correct and guru-guided. Please do not adopt any text— including the one you shared—without your sect’s authorized guidance and supervision.