Seeking Advice on How to Address My Departure

Hi everyone, I hope this is the right subreddit for my question. I recently resigned from my dream job after six months due to an overwhelming workload, often putting in 10-11 hours a day and occasionally working on weekends. The company I was with is currently contracted for a project that concludes in December, and I decided to leave before its completion. As I apply for similar positions with permanent contracts, I’m looking for guidance on how to explain my departure if it comes up in interviews. Any suggestions would be greatly appreciated!