Is one sinful if one supplicates against oneself?

A Muslim is not permitted to supplicate against himself, as the Prophet (peace and blessings be upon him) forbade it, saying: "Do not supplicate against yourselves, nor against your children, nor against your wealth. Do not choose a moment when Allah is asked for a bounty and then He answers you." He also forbade wishing for death due to an affliction, and commanded saying: "O Allah, keep me alive so long as life is good for me, and cause me to die when death is good for me." This is because wishing for death indicates despair and dissatisfaction with divine decree. Therefore, one must repent, seek forgiveness, fear Allah, and be patient with the pressures of life.