Why not using a service? As for me, it's good such services exist. I was frequently addressing the National Novel Writing Month customer service when I couldn't meet the deadline. I see they still have good reviews at https://www.pissedconsumer.com/company/national-novel-writing-month/customer-service.html. So this is good you can write everything yourself, and these tips will definitely help you. But if you feel you need help, there is nothing bad you'll ask professionals.