What is the sin of women who were forced into marriage and are now divorced and suffering from negative thoughts, and is it permissible for parents to prevent their son from marrying a chaste, virtuous divorced woman, and how can she be helped to overcome her suffering?

It is better to marry someone approved by both parents. If you wish to help the woman you desire to marry, try to convince your parents. If they are not convinced, then help her find another husband. The divorcee who possesses religious commitment and good character is not diminished in her standing by her divorce. She should remain steadfast and not be affected by baseless suspicions. It is not permissible to establish a relationship or communicate with a non-mahram (definition) woman to prevent temptation.