Was seeking forgiveness and reciting Sayyid al-Istighfar sufficient to replace the remorse at the time of the previous repentance, given that remorse was not felt until after the renewal of the marriage contract?

In summary: There is no need for anxiety or repeated questioning. Whoever weeps out of fear of Allah the Almighty over a sin is regretful, and regret is repentance, as Al-Ghazali said: "If fear is from a past action, it generates regret, and regret generates resolve. And the Prophet, peace and blessings be upon him, said: 'Regret is repentance.'"