While considerable research has focused on the emotional vulnerability and wellbeing of language teachers, limited attention has been given to these issues in the context of online teaching. This study addresses this gap by examining the experiences of 15 Iranian EFL teachers engaging in online education. Data were collected through semi-structured interviews and analyzed using thematic analysis, revealing significant impacts of online teaching on teacher wellbeing at both classroom and organizational levels. Teachers reported considerable emotional vulnerability due to organizational expectations and technical challenges, notably unreliable internet connections. Moreover, a complex interplay between emotional vulnerability and wellbeing emerged, highlighting the unique stresses of the online teaching environment. These findings highlight the critical necessity for language teacher education programs to incorporate specific training elements that address the challenges of online teaching. Such interventions might focus on strategies for managing emotional vulnerabilities and enhancing digital pedagogical skills to improve teacher resilience and efficacy in virtual classrooms.