Set yourself a goal of a certain number of words a day. Then write that number of words, every day. Hospital-level illness, death of immediate family, and your own death are the only excuses for not meeting your daily quota.
To get novel draft in a reasonable amount of time, 1000 words a day is a good daily quota. But if you don't have time for that, start at 500 words a day, or even 250. But meet your quota! It can be in actual novel draft or notes/outlines for the novel.
The only way to train yourself to write is to write. Think of it as boot camp, and do it for two months. You'll find out by the end of that time whether the rigors of literary service are for you.