Being a father can be hard work and if you constantly work without taking time for yourself, you are going to get worn out. We need to have some activity or escape in your life that helps you recharge your batteries so that you could be the best father that you can be.
The dangerous thing in this that some fathers opt for distractive activities in order to cope with the pressures of fatherhood. Taking care of stresses by turning to smoking, alcohol, or other kinds of drugs will not make you a better father, but will hinder your ability to make good judgments.
Find a hobby or some other thing at which you excel that you can do to shift gears and take your mind off things. Do not feel guilty for occasionally taking time for yourself, as this will make you able to come back to your responsibilities refreshed.
For me, I either take time to write, or to compose music. Occasionally, I join the cast of a theatrical production. All of these things help me to be a better father.