Hi Althea,
I admire you for your willingness to assume this most difficult task. Ten years ago they closed my department and transferred me to another one. I had to develop and teach courses out of my field just as you have experienced. It was a challenge and I thought about it long and hard. In the end I decided I would take up the challenge and become the best teacher I could. I love to learn so I self educated myself in the area and developed a wide variety of instructional activities. The end result is that I did refocus myself and have had a great time teaching my courses. I now receive the highest teacher evaluations in the department and I know it is due to the fact that I approach the classroom prepared, organized, and enthusiastic about my content, or at least the students think so.
I wish you much teaching success. Enjoy your students and the fact that you are helping to shape their future.
Gary