God repeatedly comforts His people by telling them that His discipline and punishment of them is always tempered with His mercy.
Thus far in history, the cup of YHWH’s wrath has only been fully poured out at one place and on one person. Only Jesus, God the Son, has drunk the full cup of wrath. In eternity future, those not in Christ will spend that time trying to finish the cup.
Isaiah 51 begins with God encouraging His people with a reminder of what He did for them in Egypt.
In Isaiah 51:12, God responds to the cry of His people with an absolutely clear declaration that He will comfort them, "I, even I, am He who comforts you." (NASU)
The question God raises in Isaiah 51:17-23 is directly related to this idea of comfort:
17 Rouse yourself! Rouse yourself! Arise, O Jerusalem, You who have drunk from the Lord's hand the cup of His anger; The chalice of reeling you have drained to the dregs. 18 There is none to guide her among all the sons she has borne, Nor is there one to take her by the hand among all the sons she has reared. 19 These two things have befallen you; Who will mourn for you? The devastation and destruction, famine and sword; How shall I comfort you? 20 Your sons have fainted, They lie helpless at the head of every street, Like an antelope in a net, Full of the wrath of the Lord, The rebuke of your God. 21 Therefore, please hear this, you afflicted, Who are drunk, but not with wine: 22 Thus says your Lord, the Lord, even your God Who contends for His people, "Behold, I have taken out of your hand the cup of reeling, The chalice of My anger; You will never drink it again. 23 "I will put it into the hand of your tormentors, Who have said to you, 'Lie down that we may walk over you. 'You have even made your back like the ground And like the street for those who walk over it." (NASU, emphasis mine)
Both love and wrath are parts of God’s character.
The Bible says that God is love and that He loves. The Bible also says that God has wrath and exercises wrath.
God pours out wrath on His people (those adopted into His family) differently than He does on those who refuse that adoption and remain in rebellion against Him by refusing the free gift of salvation found only in Christ Jesus. Those in Christ who are being crowded back into fellowship with God will never have to drink the full cup (the dregs).
Verses 20-23 above make clear that no matter how bad the situation seems, it is not unending, and it is not eternally fatal for those in Christ.
Those not in Christ will drink it all. Psalms 75:8 speaks to this:
For a cup is in the hand of the Lord, and the wine foams; It is well mixed, and He pours out of this; Surely all the wicked of the earth must drain and drink down its dregs. (NASU)
Revelation 14:9-10 tells the conclusion of the matter:
“If anyone worships the beast and his image, and receives a mark on his forehead or on his hand, he also will drink of the wine of the wrath of God, which is mixed in full strength in the cup of His anger; and he will be tormented with fire and brimstone in the presence of the holy angels and in the presence of the Lamb.” (NASU)
I urge you to cast yourself on the mercy of the Lord before it is eternally too late.