Sorry to hear about the bullying. I hope you can heal and get over it eventually. And more, I hope you find a better working environment, with kinder colleagues

Sorry to hear about the bullying. I hope you can heal and get over it eventually. And more, I hope you find a better working environment, with kinder colleagues whose company you can enjoy. "I left the previous company to seek better opportunities." There's no need to mention anything so personal, psychological or emotional at all in the next interview. You can just keep to strictly business matters, what's important for the interview and the job.