Work stress is bleeding into family time

I'm constantly checking my phone during dinner or when I'm supposed to be playing with the kids. My boss expects responses to emails at 7pm on a Tuesday and it's turning me into a jerk with my family. I snapped at my son yesterday because I was stressed about a project and I hate that. Need to figure out how to set better boundaries but I'm worried about looking like I'm not committed. This job is good money but is it worth it?