他的反应是抽身而退，埋头于工作。His reaction was to withdraw, to bury himself in work.他真的开始专心埋头于工作。He's really becoming immersed in his work.他埋头于工作以便不再思念她.He immersed himself in work so as to stop thinking about her....

“埋头于”的英语可以翻译为：up to the eyes，be wrapped up in ...