It seems to me that your biggest problem (like some posters have already stated) is that you've been running from method to method. You haven't tried anything long enough. You only did ewhoring and adfly for a weeks? Only promoted on FB for 2 months? Dude, that's not enough time.
Stop jumping around from method to method and pick one, just one. The methods you've listed might not be the best, but they are profitable. And if the method isn't working after a few weeks or a month, don't stop. Tweak it. Dombyran973 and Techxan gave you two tweaks you can use on your dentist site and here's another: You pitched your site to the local dentists in the area and no one wanted it. So sell the leads. Or join a few CPA networks and promote anything related to dental (teeth whitening for example) on your site. If you were able to rank a site #1 on Google, there is a way to profit from it.
But you've gotta stop chasing method after method and giving up after you've only put a few weeks or a month into it. Some of the biggest players in IM didn't start to see a profit until YEARS after they started.
Here's the bottom line: Internet marketing (or business in general) isn't for everyone. Need a steady paycheck? This isn't for you. Don't want to constantly learn about different strategies like PPC of PPV? This isn't for you. Don't want to adapt at the drop of a dime due to an algorithm or a policy change? This isn't for you. Don't want to work 2 days straight staring at a computer screen testing, tweaking, researching keywords, etc.? Then this definitely isn't for you.
So maybe you do need to take a step back and re-evaluate what it really is you want out of Internet Marketing, if you want anything from it at all. But you also need to realize that we're all going to get discouraged from time to time, that's normal. But what separates the winners from the losers it that the losers quit; but the winners only see it as a setback and they dust themselves off and try again. So...which one are you?
"Don't cry to quit. You're already in pain, you're already hurting. You might as well get a reward from it." - Eric Thomas