As for the "beginning of sorrows," we are seeing all that NOW.
Nation against nation, kingdom against kingdom, famines, pestilences, earthquakes...

Now learn a parable of the fig tree; When his branch is yet tender, and putteth forth leaves, ye know that summer is nigh:
So likewise ye, when ye shall see all these things, know that it is near, even at the doors. Matt. 24:32,33


The fig tree started putting forth leaves in 1948, when the Jews went back to the land.

There is no proof in that passage that the "beginning of sorrows" is the first half of the tribulation.