Leaving mainstream work to set out on your own is hard. It's trying and downright difficult at times, especially when you start to become bogged down by bills and a lack of income or by the stress of being all roles in the business in a one-woman band.
It's easy in these times to remember mainstream work fondly, the security of a regular paycheck, the responsibilities far less and more manageable. It's during these times that you must remember why you started.
You began this journey because you had a dream - whether that be to change the world, to fill a gap in the market or to work for yourself: for the freedom, the future security and the personal accountability for your own (and your business') growth and survival. You had a dream, you made a decision, you left the mainstream to venture out on your own with a vision or idea and a heck-of-a-lot of passion and you are pushing towards something greater.
Keep going. Keep pushing. Strive to achieve that goal. Remember why you started.