Tabitha and Jim’s marriage was doomed from the start.
During the first season we learn that they were going to divorce and the only reason they have not is that they ended up here. While they decided they didn’t want to divorce, they didn’t actually fix any of their problems. They were put into a high stress situation that was less stressful initially if they dealt with it together.
The problems in their marriage have become more apparent this season, their argument gave us a lot of insight into why what happened, happened.
Unless Jim stops with the self pity and victim complex and takes responsibility for his actions and his behavior their marriage will be doomed.