I think this is something we all need to hear. I've been trying to find "the best" dentist to remove my fillings, and yeah, I've gotten quite frustrated to the point of tears sometimes. It's frustrating because we don't always know what to do, what is really best. It takes a long time to research and try different things.
I've been trying to eat a less-allergic diet, and I quit the daily wine and coffee cycle cold turkey two weeks ago. I've cut out all added Sugar and try to only eat what God made or what I personally make using ingredients that I know about. I had an excruciating headache for twelve days straight, but I feel better now. Although, my ears still ring all the time.
Every day that I wait to have my fillings removed is a day that I can learn more and try to become more healthy so that I can "do it right". But yeah, I really needed to hear that I don't have to get everything absolutely perfect. You're right! God built in a little "wiggle room" in our bodies. We can just concentrate on several little "baby steps" in the right direction on our path to great, abundant health.