Should I return the money I squandered due to my negligence in studying, and how can I confess this old matter to my father?

Repentance is obligatory for lying to the father, but there is no need to return the tuition fees to him for several reasons: the presumption that he would have continued the study path and paid the fees for the repeated year if he had known, the lack of intent to fail, the possibility that the father knew and chose not to confront, and that he did not fall short in matters greater than the fees for that year. Therefore, do not inform him of what happened, as there is no benefit in doing so, and to avoid embarrassing or saddening him.