Son, sustenance is of two types, one that you seek, and the other that seeks you. Thus if you do not seek sustenance it will seek you. In the world your share is to that extent which can stand you in good stead in the Hereafter. If you grieve even what you have lost, then you should grieve over everything, which you have not got. Do not be like those people who are not impressed by any advice, but are moved by accusations. A wise man takes a lesson from even an ordinary lapse.
"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari