White Teeth

I've given up trying to get white teeth. I don't smoke, drink one cup of coffee a day. There is no reason my teeth shouldn't be brilliantly white. It is especially annoying confronting people who I know are much less healthier than me, who couldn't jog around the block, whose teeth are whiter than mine.
I floss and brush up and down and use bacteria killing mouthwash, which I gargle expertly. If gargling were allowed on resumes, I'd be a CEO. A big disappointment has been Colgate Optic White toothpaste, which I've been using for months. It supposedly contains the same ingredient found in whitening strips. I have seen no change whatsoever in my condition. But now my gums hurt because I stopped using the sensitive toothpaste. Of course I could brush twice a day, using each brand, but what kind of message is that sending to my teeth? This is a confused, insecure man I'm chomping for.
I tried this gel which you carefully place on your front six teeth, upper and lower. You're not supposed to get it on your lips because they will stick together. Well, once that stuff is applied and you close your mouth, it's gonna get on your lips, which is what happened to me. Then I did get these strips, which I'm afraid to use. Suppose I stick them on and they won't come off? Or what if I start to gag? I gag easily; the list of gag prompts is long--Michael Myers, open mayonnaise, dust motes on pasta, Jimmy Fallon's monologue, facial punctures for jewelry purposes, bearded men with nose bleeds, Ken Burns' documentaries, the words fecal matter--just typing this makes me gag. My choice-brown teeth or shirt vomit.