At Mass after the Lord’s Prayer the priest prays, “Protect us from all anxiety as we wait in joyful hope for the coming of Our Lord Jesus Christ”. This means we await the End of the World in joyful hope as well, so even if it is a time of terrible tribulation, it is also the time of victory which brings about the reign of Christ the King. Yes, fearful and exciting at the same time. I don’t know if I should hope to live to see it or not.
There have been a number of Saints who have prophesied on the Three Days of Darkness. You can google it to look them up.
I am aware of no official Church teaching on what the end of the world will entail, and we are certainly not bound to interpret the events described in Revelation as literal. You’re operating, it seems, from the assumption that the end will come as described in Revelation, complete with Four Horsemen and the seven-headed dragon.
To borrow a thought from Rosencrantz and Guildenstern are Dead: Since we don’t know what [the end] will be, it is illogical to fear it. It might be…very nice.
Then again, it might come as a result of the death of our Sun, or the impact of a colossal asteroid, or a global thermonuclear war.
The bottom line, as pointed out above, is that in Mass, we pray that God will free us from our fears so that we can aniticipate Christ’s return in joy.