True, the healthier you are, the more likely your body can fight it off. Keep in mind your immune system is fighting off thousands of strains of viruses and bacteria every day. Anyhow, there isn't really much you can do to protect yourself other than wrapping it. As long as your putting on a condom, this will fight off the bacterial infections. Also, and people may not know this, but nearly everyone has been exposed to HPV. If you had sex before, you've probably been exposed to it. Condoms don't protect you from it. It's just one of those things you have to live with (there's also no way to test for it). For a guy, there are almost always no symptoms. Think if it like smallpox or shingles and move on.
So there is really nothing we can do but hope for the best and keep getting tested. Really that is we can do. It's that or keep jerking off.