Is a mother’s prayer against her son for failure and her displeasure with him in this world and the hereafter, which was repeated on Laylat al-Qadr, the reason for his academic failure, the deterioration of his social relationships, his contracting multiple illnesses, and his inability to find work until now?

The mother's right is great and comes after the right of Allah Almighty, and showing kindness to her is obligatory, as stated in the Quran and Sunnah (definition).

As for disagreement with the mother during childhood, there is no accountability upon you for it due to not being religiously obligated (mukallaf), and her supplication against you at that time is not permissible and might not be answered.

As for disagreement after puberty: if you were in the right, then you must forgive, pardon, and show kindness to her. If you were unjust, then you must repent sincerely, seek her forgiveness and رضا (satisfaction), and involve someone influential with her.

Your failure or illness might be due to your mother's supplication against you, hence you must seek her forgiveness and رضا (satisfaction), for her supplication for her child is answered.