What is the remedy for the feeling of intense sadness when peers excel, and wishing them ill?

Striving for academic and other success is a good and desirable thing, for Allah loves the highest matters, and a strong believer is more beloved to Him than a weak believer. If you exert your effort and someone surpasses you, do not grieve, but rather be content with Allah’s decree, for Allah's choice is better than the servant's choice. Do not wish for what others have been favored with, and do not envy them, for envy harms the envier before the envied, and it is a characteristic of evil people. Sense Allah’s wisdom and justice, for He gives each person what they deserve. Make your true competition in matters of the Hereafter to gain Allah’s pleasure, for this world is blameworthy if it is not an aid to the Hereafter. Remember that your faith is not complete until you love for your brothers what you love for yourself. Exert your utmost effort, then be content with what Allah has allotted for you, and do not envy anyone.