Money's one of those issues. When my monkey-brain pictures me as a homeless bag lady in about 2 weeks, I need some ammunition. One of my strategies is to understand that when it comes to money, writing is a feast-or-famine endeavor.
Traditionally, writing as a means of earning a living has been fraught with insecurity. Sure, there are writing day-jobs that provide regular paychecks, tech writing, salaried journalism, marketing and sales copy writing, that sort of thing, but that's another topic.The conventional model is that you write, you submit, you wait... Sometimes you wait a little and sometimes you wait a lot. Sometimes you get paid a little and sometimes you hit the jackpot. For almost all of us, quitting our day jobs under such conditions is insane.
Selling on proposal, having those contracts in hand, offers a measure of improved security. You're no longer wondering if you're going to sell that book, and you know how much and when you'll be paid for it. (All you have to do is write and revise it to editorial satisfaction, often no small matter.) Say you move on to having a number of books in print and more under contract. Setting aside the unpredictability of sales from one royalty period to the next, this is a different kind of insecurity. You know that twice a year you'll get a check and you know when. You might be able to guess the amount. But you still have the perennial nerve-wracking challenge of going for long periods of time without income, of having to make that money last. (In addition, you may be buying your own health insurance, adding to your regular expenses.) While it might be wonderful if all your bills came due only when you got a royalty check, that's unlikely to happen.
So even if you're a successful writer, you still have to tolerate a certain amount of uncertainty, and you have to manage your money on a different time scale than the rest of our society. We don't get taught how to budget 6 months at a time; we do get taught how to budget 2 weeks at a time. There aren't good role models on how to think about recurring expenses, emergencies, large infrequent expenses like property taxes or replacing vehicles or appliances. Or how to make sure our "inner child" muse is taken care of while we attend to the more mundane economic necessities.
When you buy a house for the first time, the bank will likely want to impound funds to pay for property taxes and homeowner's insurance. I take a cue from them and use a similar technique, self-impounding, for a wide range of expenses, not only taxes and homeowner's insurance, but auto insurance, estimated taxes and the like. Occasional expenses like clothing or vacations or holiday gifts would work well this way. The self-impounds then become a monthly expense. In those long times between royalty checks, I sometimes get in arrears with myself. I keep track of how many months I still owe myself, and catch up when that check comes. The system isn't perfect, but it does help me to avoid that total panic when I'm faced with one of those large, infrequent but predictable expenses.
The new self-epublishing venues (Kindle, Pubit, Book View Cafe) allow the writer much more timely information about sales, not to mention more frequent payments. By and large, I have found their accounting/sales reports to be easy to read, unlike the baroque forms of the traditional royalty statement. It is immensely helpful to be able to predict how you will receive next month, based on sales information that might be updated daily. The corresponding pitfall is that having this information so available can act like an engraved invitation to obsession, monitoring every uptick or drop in sales instead of writing that next book. For me, it's important to keep my priorities straight. I don't play the stock market and for me, watching daily sales figures amounts to the same black hole of time and energy. If I find myself preoccupied with checking my accounts, that is a signal that something else is going on. If I'm trying to assuage my anxiety, then I might do much better to step back and look at whether my fears are rational or what other part of my life is troubled.
When in doubt, dive back into the novel at hand. It's the one thing I can do to create financial well-being. There are no guarantees that this particular novel will generate lots of income, but if I give up--if I allow myself to be distracted and unfocused--then I will ensure it does not!