You know the explanation from pulp fiction where John Travolta explains that he is like a race car driven in the red all the time? Well, you can drive yourself in the red area for quite some time and yes, you are getting a little used to it.
But that doesn't mean you need or should. You need to look after yourself.
And one important thing here is to learn to say NO. I know, we all want to be the go-to guy for topic, but it doesn't help anyone, if you always work on your limit.
One great sentence, just visualize it;
I do not have time to sharpen the saw, I need to saw!