Woman going out to fulfill a lawful contract

Q: Praise be to Allah, I am a married woman and my husband allows me to work as a kindergarten teacher. The school required my husband's signature of approval on my employment contract stipulating that I would not quit without prior notice. One day we had a dispute and my husband sent me to my father's house. When he took me to my father, he did not say whether I was to remain in the house and never go out or not. So I stayed at my older brother's house until the end of the academic year. Because this was during the final exams, which usually lasts for two weeks, it is very difficult to find a replacement teacher. However, when my husband knew I stayed with my brother, he became very angry and accused me of going out without his permission. I only left my father's house to stay with my brother who lives nearer to the school. I wished to fulfill the contract wherein my husband agreed to my not quitting my job abruptly without ample notice. (Part No. 19; Page No. 167) Later, my husband ordered me to return to my father's house and remain there until the problem was resolved. I refused because of my contract obligations that do not permit unauthorized absences. After those two weeks (14 days) when the summer vacation started, I returned to my father's house. Some righteous people mediated our dispute and were able to resolve the problem; thus, and I am back with my husband now. My question is: Am I considered a sinner for going out without my husband's permission, although he had previously agreed to let me work for the whole year, based on my contract? He reproached me and said I ought to have returned to my father's house, even if he had signed the contract. I am confused. Is it permissible for him to revoke my employment contract?