It took me several years to save money for the trip and during this time, my fears (all of them) were gradually forgotten and replaced by the excitement of the big adventure. Anxiety over quitting my job became delight in leaving it – who likes to work? I decided not to worry about finding a new job until the time came, if it came: you never know what opportunities might arise on the road. And you never know what changes might occur within yourself: some people 'find' themselves through travel and end up changing careers or go back to school instead of finding work.
One thing to remember: taking a year off to travel isn't a 'bad career move' – as a traveler, you develop people skills, planning skills, negotiation skills, budgeting skills, and decision making skills. You gain knowledge and wisdom and having done it exhibits to others that you are a person of strength and confidence: attractive attributes to potential employers.
Some people take sabbaticals from work instead of quitting. If it's possible to make this arrangement with your employer, there's no reason to worry.