Having two jobs is tiring

I have been getting steady writing projects for the longest time and though I am thankful, I feel that I am always tired. I have not enough time left for myself and other things that matter because my office job still stands. The office job has been a regular source of extra income, but I do not feel fulfilled each time I go to the my workstation and have to do what I do. My colleagues are great, nobody bullies me, but I am not happy. Hopefully I get to push through another year and get to save as much as I could. After that, I must decide whether to stay or go. Nobody's getting any younger and a person's physical self can only do so much.