Praise be to Allah.
It is not permissible for a man to curse life if he feels fed up, because the Prophet (peace and blessings of Allah be upon him) said, in a hadeeth qudsi (holy narration) that Allah says, “The son of Adam offends Me by inveighing against [the vicissitudes of] time, and I am Time. In My Hand is the alternation of night and day.” It was also narrated that the Prophet (peace and blessings of Allah be upon him) said: “Do not inveigh against time, for Allah is Time”, i.e., He is the One Who is controlling time. So when man is afflicted with calamity, he must be patient and seek reward, for Allah has enjoined patience.
And Allah said to His Prophet ` (peace and blessings of Allah be upon him) (interpretation of the meaning):
“This is of the news of the Unseen which We reveal unto you (O Muhammad); neither you nor your people knew it before this. So be patient. Surely, the (good) end is for the Muttaqoon (the pious).”
Let man know that no matter what happens there is something worse than it somewhere else in the world. If he understands this, then his problems will become easier to bear.
And Allah knows best.