Why are the books of Jeremiah and Lamentations one after the other?

They are like 1 and 2 Jeremiah. Jeremiah is warning the people about what will happen, and then after it does happen he is expressing his deep sorrow in Lamentations.

Speak Jeremiah, Thus says the Lord: Who is Jeremiah?

Jeremiah was a priest who was called the weeping prophet because the Lord asked him to deliver the message to Judah about the disaster that was coming. Jeremiah warned about it, watched it happen, and wept over it.

My Living Water is spurned and ignored: How is Living Water spurned and ignored?

Living Water is not actual water that you drink for your body, but it is something we need just as much as drinking water! God created us to love us and for us to love Him more than anything else. It is like our hearts are thirsty all the time for Him. He alone can quench (fill) our thirst. God is saying here that His people were not coming to Him when they were thirsty. They looked at His love for them with ungrateful hearts and paid no attention to Him.

Digging their own wells that always go dry: What does “digging their own wells” mean?

They were trying to fill their thirst for God with other things, and even very evil things.

What does” always go dry” mean?

They may find something to fill their thirst for just a short time, but it would not last long, and it would never truly satisfy them.

Disaster’s approaching, go tell them why: What disaster was approaching?

This was a warning before the Babylonians wiped out the southern kingdom of Judah, and captured them. Why was disaster approaching? God allowed Jerusalem to be destroyed and for the people to be taken captive to discipline them for their wicked behavior and to cause them to see their need to look to Him.

Weep Jeremiah, Jerusalem’s gone: Didn’t he say this would happen?

Yes, but he was still very very sad about it.

The Lamentations–a sad funeral song: What does Lamentations mean?

It comes from the word lament which means to weep, to express sorrow and to mourn. This book is written in the kind of poetry that is sung. This is a sad funeral song of Jeremiah expressing his sorrow for the ruined city and people in it–many who have died.

Hearts of the captives have fainted away: What does this mean?

Those who did not die were taken captive and they had no more courage.

Yet God’s lovingkindness is new everyday: Why is this in the lament?

Jeremiah shares these beautiful words, because this is what gives him hope and he wants to bring hope to those whose hearts have “fainted away,” and to encourage the captives to seek the Lord’ He says in Lamentations 3:22-23 ~NASB

“The Lord’s loving kindnesses indeed never cease,
For His compassions never fail.

They are new every morning;
Great is Your faithfulness.”