Lamentations is an acrostic poem built up upon twenty-two letters of the Hebrew alphabet to help those who wish to memorise it. Its overall message is one of sorrow at the overthrow of Gods' people and destruction of Jerusalem the capital city.
It was as a result of their disobedience in not keeping the conditions of the ancient covenant God has made with them and so the consequences were thoroughly deserved. But God tempers His justice with undeserved loving kindness and mercy we call unmerited grace. The affirmation of the promise of eventual restoration of His people to a meaningful relationship leads to new hope of its realisation.
For us it is a daily restoration to blessing when we sincerely confess our many failures of the previous day. Where the beginning of each new we fear will be a poor start let us ask God to make the day end well! Grace is given. 1 John 1:9.