Hi Thea,
So happy you didn't give up and am glad you found your niche. Anything health related is still pretty competitive so if you can specailize in a certain area, certain types of products or a particular ailment that you products would help - that may be a good way at least to get started. Remember not to sell the product but the benefits and what it can do to help people feel better, look younger or whatever.
For advertising - here is an AWESOME FIND! It's a company I'm soon going to be representing, but I'm also buying some advertising with them because the ad buys are so incredible right now. It's a new blog ad network and they have some DYNAMITE ad pricing.
http://performancing.com/partners. Click adverters then view blogs by topic. They have lots of health blogs - most are $25 a month or less. Obviously find the ones with highest traffic that are a good match for your products.
You can also find some really good buys at
www.adbrite.com I do lots of advertising there.
For FREE traffic you should start blogging. Write 2 health related articles a day filled with great info and all the right keywords. Then submit to all the rss feeds using
http://www.feedshot.com/. Use the paid version which is a WHOPPING $1.99 and well worth it. Then after every article you publish to your feed use pingomatic or pingoat to ping all the servers to let them know you updated. Building up a good blog is one of the best ways to get free traffic.
Hope this helps and best of luck!