You don’t have time? Make that time. This is essential. Only you can make and defend the time you need for your work. Nobody is going to give it to you. I know, I know, it’s horribly hard. Writing is outrageously time consuming. Of course, if you have an equally time-consuming job or heavy personal responsibilities, you’ll be slowed down. But you must make time or you will not write at all. Simple as that.