Being a web designer, I see a common problem that website owners face.
Time and again I see online businesses quit after just 4 or 5 months online. Their reasons are normally down to disappointment. Their expectations were set too high in terms of traffic and sales, given that the launch of their website and following months is usually the quietest time for sales (as nobody knows about the site), unless you plough a lot of money into Google Adwords. If you look at sites that deal in dropped (or dropping) domains, you'll see just by the domain names themselves, it's a real business graveyard.
Moreover, business owners become obsessed by the aesthetics of their website when it's being designed and developed - overlooking usability and accessibility. When the site goes live, they finally get their business heads on and are concerned by how well the site actually converts visitors into customers.
My advice is to keep going, and get past "the dip". In some ways, being a success online is simply ploughing through longer than your competitors do. Remember that all companies must start just as you did, so if you've been trading online for even a year, you have a big competitive edge over brand new start ups just by the virtue of your longevity.
What amazes me is how little effort people put into their websites in terms of content. Many see their website launch date as the day that content creation stops and marketing starts. In reality, content creation should be as on-going as marketing has to be. A website with a good "backend" and content management system should encourage you to keep writing articles and information on your site.
Above everything else, find a product or service to sell that you are passionate about. This makes everything else so much easier to do. You will find content creation and the promotion of your website that much more natural to do.