Brett
One of the biggest challenges that I faced was building up my own self confidence when I first started out. If you have the skills and you understand the technology there really should not be that much doubt but it seems until you really get going and build that portfolio there is plenty of doubt.
Once I became established, and that took about a year maybe two, the problem that I had then was competition, there was plenty of it, so what I did I became very good at one aspect of web design. I made my aspect dynamic data. I became the goto person for questions on that aspect of web deployment long before CMS's became popular. Once you find your niche you build a reputation as long as it is a good one your business will grow. Whether you are working for a large corporation, small business or independently. I have found great satisfaction in all aspects, as I have tried them all.
Find a niche in the market that you are comfortable pursuing, become very good at that aspect of web design and then pursue it. Become one of the best in that area. Be patient and persistent and it will pay off.
By the way, in web design there are so many aspects of that field no one knows it all. We all have found our specialties and call in other people with their specialties when we work independently on large projects. Freelancing can be very rewarding and really force you out of your comfort zone as you are forced to learn new stuff. For new clients. But you have to be able to get through the feast or famine period. What I mean by that is you will have months with lots of revenue rolling in and you will have months with no revenue rolling in.
You have to be able to deal with that to be successful.