Don't be Sad
Strive for your sustenance, but don't be covetous
The Lord of the worlds provides for the worm in the ground:
(There is not a moving [living] creature on earth, nor a bird that flies with its two wings, but are communities like you.)
(Qur'an 6: 38)
Allah provides for the birds in the sky and for the fish in the sea:
(And it is He Who feeds but is not fed.) (Qur'an 6: 14)
You are worthier than a worm, bird, or fish, so don't worry about sustenance.
l have known people who were stricken by poverty simply because of their distance from Allah. Some of them were rich and healthy, but instead of being thankful they turned away from obedience to Allah, they abandoned prayer, and they perpetrated major sins. Allah took away from them their health and their wealth, replacing these with poverty, sickness, and anxiety. They were then afflicted with hardship upon hardship, calamity upon calamity.
(But whosoever turns away from My Reminder; verily for him is a life of hardship...)
(Qur'an 20: 124)
(That is so because Allah will never change a grace which He has bestowed on a people until they change what is in their own selves)
(Qur'an 8: 53)
(And whatever of misfortune befalls you, it is because of what your hands have earned. And He pardons much.) (Quran 42: 30)
(If they [Non-Muslims] had believed in Allah, and went on the Right Way [i.e. Islam]. We should surely have bestowed on them water [rain] in abundance.) (Quran 72: 16)