In the post-pandemic period, an increasing number of students have been using online learning environments, as students find them more convenient and feel less academic pressure. However, some students are comparatively disadvantaged due to their lack of access to a fast network or a powerful computer to attend online classes. Consequently, students may feel isolated due to their lack of internet connectivity. Based on conservation of resources theory, we aim to provide empirical evidence that various forms of student interaction in online learning classes mitigate negative psychological outcomes, such as distress and anxiety problems. A single-stage cluster sampling design was used for data collection. An online survey of 422 university students in Hong Kong was conducted in 2022; the students participated in online learning classes during the year. Partial least squares structural equation modelling was used for data analysis. The results showed that student-teacher, student-student and student-content interactions can reduce students' psychological distress by reducing their performance and technology anxieties in online learning environments. Practical performance and technology anxieties served as partial mediators of the association between online class interactions and psychological distress. Interaction did not have a direct effect on psychological distress. When using blended or online teaching and learning modes, more interaction should be promoted. For example, group exercises can be introduced by teachers during tutorials to enhance student-student interaction, teachers can use polling exercises to encourage student-teacher interaction and virtual reality environments can be introduced during classes to enhance student-content interaction.