The outbreak of COVID-19 in 2020 put the education system worldwide in a critical situation with a sudden shift from the traditional face-to-face to the online mode of instruction. Many studies have been conducted over the past two years to investigate teachers' struggle with this abrupt transition; however, a complete picture of their emotional battle throughout the whole pandemic has not yet been depicted due to the short study durations. By analyzing rich datasets collected from semi-structured interviews with nine EFL teachers working at the tertiary level, we were able to outline their emotional changes and coping strategies for emotional regulation throughout the span of two years, from the beginning to the end of the mandatory online teaching period. It was found that, in general, the participants' changes in emotions can be illustrated with a wave curve, which is divided into five phases with quite distinctive characteristics. The findings also highlighted the complexity and changeability of teachers' emotional experiences, as well as the five major coping strategies utilized by the teachers to enhance their emotional well-being. Finally, several recommendations applicable for both teachers and stakeholders in future crises are proposed.