I always loathe coming home after work. What can I do to make myself more tolerant?

Home with my family is the very last place I ever want to be and I don't know why. This all started a couple weeks ago. It happened gradually. At this point I can hardly stand being in the same room as anyone in my family, let alone talking to them. I work extra unpaid hours at work just so I have am excuse not to come back. Its definitely not good and I want to know how to make myself be calmer and more tolerant. My family does nothing wrong.

TL;DR: I avoid my family because they make mad even if they do nothing wrong. How I fix?

EDIT: I don't have a ton of time right now, but later when I do I'll out up a bunch more details.