Same boat here basically.
I've been doing web design and development since I was 10. I've been making money doing it since I was 14. I moved out on my own when I was 15.
I turn 25 one week from today. I'm now married with two kids. I live in a small town of approx 35,000 people in Saskatchewan, Canada. We are currently renting a town house for around $700/mo. Basic utilities are around $150/mo.
With my wife working full time with a wage around $13.50/hr it certainly works for us. I stay home with the kids (daycare is expensive!) and work around her schedule when it comes to meeting with clients, etc.
The goal is when both of my kids are in school, I will be able to really focus on the business and take on even more clients. Eventually rent some office space and grow from there.
Build it up little by little and eventually you will be comfortable. Around here you can make around $35,000/year before paying taxes. That certainly makes it easier.