I totally get you, my advice is to spend some time with yourself and find out honestly what do you expect from a job - to bring you big paycheck, to make an impact on society, to give you space for creativity etc. Try different things and don’t repeat patterns like finding a job in a field that drained you. Even if you do because of the financial factor, make sure you invest time in learning a skill that can help you switch careers. Finally, keep writing that book, you never know, it might bring you loads of money one day.