I only bring in about $2500/mo in freelance design/development work because I've not yet had success in finding good clients. Mostly I've ended up with idiots from Craigslist who insist on wasting all my time and then drag their feet when it comes to payment. Then you add scope creep and people insisting on meeting in person for a low budget project and I make almost nothing.
I had the same problem 5 years ago. It's experiences like these that got me out of freelancing completely. It's exhausting and isn't worth it in my opinion.
I really need to work on getting better clients!