The speaker is Jerusalem herself. She is no longer a "princess" but a "widow." She whose streets were once full of people, is now lonely. Her friends have become her enemies. Even her roads mourn because they are no longer traversed by happy families traveling to celebrate the Jewish festivals.
In verses 8 and 9 she recognizes her sin, but at this point seems more embarrassed at the disgrace than anything else. The pagans have seen her nakedness so she "groans and turns her face away." "The Lord is in the right," she says. "I have been very rebellious, BUT…"
Look at poor little me. God has been so hard on me. Everyone is laughing at me. No one will comfort me. See my suffering. Yes, she is suffering badly, far worse than any of us ever have, but something is missing, even in her confession of sin. She has more to learn about the purpose of punishment and the correct way to view it.
However, the grief itself is not wrong. God has made that plain throughout his Word. Even righteous men are shown to grieve, Abraham, David, Hezekiah, and Paul among them. Even Jesus cried. Paul told the Roman brethren to "Weep with those who weep," not look down on them and rebuke them for crying. The promise we have ultimately is that God will wipe away all the tears from our eyes—then, not now.
But our grief is to be different. "We sorrow not AS those who have no hope" (1 Thes 4:13), not "We sorrow not." And if on occasion, our grief is caused by our own sin, as with these people, we have an even larger obligation in our grief. Godly sorrow works repentance (2 Cor 7:10). These people are still working on that. Eventually they will get there, but not quite yet.
God made us to grieve. It is human nature to miss a loved one, to be frightened by a bad diagnosis, to be overwhelmed by a loss of physical things, and especially by a spiritual loss. It is even correct to grieve in such a dramatic and lengthy way as these people did. As sinful as they were, when you read these laments and see what they went through, you still feel compassion and pity for them.
But as with everything God made, He made grief to serve a purpose. It can bring repentance, it can bring strength, it can bring clarity, and help us learn priorities. Use it, not as self-pity, but the way He intended.
Restore our fortunes, O LORD, like streams in the Negeb! Those who sow in tears shall reap with shouts of joy! He who goes out weeping, bearing the seed for sowing, shall come home with shouts of joy, bringing his sheaves with him. (Ps 126:4-6)