Does the first half of the tribulation get progressively worse?
Yes. The first three and a half years are not a utopia; after perhaps a few months of Antichrist's apparent control, the remainder grows progressively worse. War, invasion in Israel, and famine crescendo toward the midpoint, where the sixth seal brings a great earthquake and the day of wrath.
Les explains that the first three and a half years will not be a Sunday school picnic or a utopia. For maybe just a few months, the Antichrist will seem to have everything under control, but the remainder of that three and a half years will get progressively worse. The war and the invasion in Israel, along with the attending famine, are already beginning to crescendo. Then at the midpoint of the seven years comes a specific great earthquake, the sixth seal. At that time the sun becomes black as sackcloth and the moon as blood, likely because of cataclysmic events and pollution in the air. Verse 17 declares that the day of His wrath has come.