Most people would agree that you can't get rich working for someone else. It just isn't a common thing. The frustration with working under someone else can lead to dissatisfaction in the workplace, thus motivating you to start out on your own. However, using your current job to help provide stability while you are working on the business is a great idea. The notion to just up and leave your currently stable income is a bad idea. Getting your new business of the ground will require a level of effort beyond your current job, but the rewards will be worth it. The bottom line is that there is no need to do an all or nothing approach. Gradually starting your business in a small way while working at your job can help you stay passionate about the idea without having to go out on a limb all at once.
One of the best ways to uncover your motivation is to write down what it is you want in life. Taking the time to be honest about what you want in all areas of your life will help to clarify whether or not starting a business is really for you. Once you have written a clear idea of your business needs, you can start to refine it by setting some goals. This exercise is vital because it will force you to get clear on what you are truly interested in. Your motivation will become quite apparent when it's down in writing!
Having written ideas will help you with your short and long term goals. Although one of your goals may be to completely support your family with the income from the business, you'll need to get customers first. It will show you what you can do today to get started. You