Jeremiah has delivered the message from God to the people.  He laments that they have not listened and are suffering as a result of their sins, even the innocent suffer.  He even says that the punishment of the people in Jerusalem is greater than the punishment of Sodom.  Sodom's destruction was instant. Jerusalem's inhabitants experience prolonged suffering.

The following words of Jeremiah are echoed later in the words of Paul.

Lamentations 3:40
Let us examine our ways and test them, and let us return to the LORD.

2 Corinthians 13:5
Examine yourselves to see whether you are in the faith; test yourselves. Do you not realize that Christ Jesus is in you-- unless, of course, you fail the test?

Earlier God had told the people that there would come a time that He would not listen to them.

Lamentations 3:44
You have covered yourself with a cloud so that no prayer can get through.

Have we as Believers in Jesus “covered ourselves with a cloud”? If so how have we done that?

Lamentations 4:10
With their own hands compassionate women have cooked their own children who became their food...

This very thing was foretold in Ezekiel 5.

We are told that God's wrath was poured out on the people because of the sins of the prophets and the iniquities of the priests. It is very clear throughout Scripture that God holds spiritual leaders to account.

Jeremiah laments in Chapter 5 that "the crown has fallen from our head."
This is the crown of Zedekiah, king of Judah, whom Jeremiah earlier refers to as "the Lord's anointed".   Zedekiah is the last of Judah's kings.  The crown of kingship will not return to Jerusalem until Jesus returns.

Even though much of Jeremiah’s lamentations are indeed expressions of grief, he includes this most wonderful of Scriptures.

Lamentations 3:22-23
Because of the LORD's great love we are not consumed, for his compassions never fail. They are new every morning; great is your faithfulness.

What a great verse for us to ponder.