Truth,
Sometimes, its impossible to fix while in the situation. Sometimes, the partners bring out the worst in each other. A friend of mine who divorced from her first husband told me that aside from the regular marital issues they had, they brought out the worst in each other. They fed off of each other’s frustration in bad ways.
After their divorce, they were able to truly get the help they each needed. She has moved and and is happily married. He still needs to work on his issues and has not found someone.