I love talking to various people about writing as a career. The misconceptions I hear often make me smile. When I say I'm a writer, many assume I must have at least a few published books on the bookstore shelves. (I don't.) Or, they think it is not a "real" job but a hobby that anyone who wants to can successfully pick up in their spare time. (It's not.) If they only knew!
Though it's not unusual for writers to have to take other jobs in order to pay the bills and keep food on the table, we consider writing our only real work. My dad (known by most as Pop) had a great saying: "Support your passion until your passion can support you," wisdom he'd learned from experience.
Do whatever you have to in order to support your writing. No matter what else you do, don't stop writing. The "odd jobs" Laurence speaks off may feed your body, but, if you're a real writer, writing feeds your soul. Though we all laugh about our chronic procrastination problem and the pain of writing, that doesn't change our awareness that we MUST write. A little part of us withers if we don't use our gift, and we feel stifled when we fight the need to create that compels us to put pen to paper. It's in everyone's best interest that we write, because we become ill -- "sick at heart," so to speak, when we don't get the stories out and when we don't let the muse out to play.
So, work at whatever odd jobs you must, but don't neglect your writing. Find a way -- at lunch, early in the morning before anyone else is up, late at night when the kids are in bed, whenever you can spare even a moment -- to write. We all lose when writers don't write!