What should a religiously committed person do, who helps others, but feels extreme distress and frustration because his family has turned against him after his projects failed, and he feels that his prayers are not being answered, and he is assailed by satanic whispers?

The questioner's patience with his family's bad treatment and forgiving them is better, due to the great reward therein, and Allah's support and assistance, as indicated by Qur'anic verses and Prophetic hadiths that encourage patience, forgiveness, and suppressing anger.