Strict Jain answer: Yes, it is still a fault/sin at the level of thought if the intention of self-harm arose.

In Jain dharma, himsā begins in the mind also. So even if the act was not done, a harmful intention creates karmic bondage.

But if the person has truly repented, done pratikraman / prayschitta, and resolved not to repeat it, then that repentance is spiritually meaningful and helps reduce and purify the karmic burden.

So the strict answer is:

• Thought of self-harm = yes, it is a sin/fault in Jain view
• Not doing it + sincere repentance = purification begins
• If fully repented, one should not remain in guilt, but continue vigilance and repentance

In short: Yes, it was a fault, but sincere repentance matters and can purify it.