When do you say stop?

When you start allowing work to invade your thoughts, sleep, and free time, how can you ever stop it like you used to? I always did a great job of finishing work by 6 then not giving a moment's thought to the work I left behind. Now, its how can I sleep faster to get to work earlier to try and get a head's start on the day. Its not coz anyone's pressuring me. Quite the contrary, I am the one who wants to do things right, on time, and as efficiently as possible. When did this become me? When did I allow this invasion? The problem is, even though it may just sound like any normal person giving a priority to their career, I feel drained alot which demotivates me suddenly. That's NOT good and makes me burn out so much faster. I need to regain my life back! Not to avoid work, but to be able to do my job in a way that would satisfy me!