There's nothing odd about you, it's me! Up til the age of five I used knife and fork in opposite hands. In cricket I bowl right handed and bat left, in golf I play left, in tennis/ badminton/ squash I play, mainly, right but can swap rather than play backhand. I unscrew things with my left hand and if I make a cup of tea I use either hand, whichever is nearer to sugar/milk/etc.
No use asking a GP, they're all quacks!

my brother has dyslexia, and he did the fork and knife in opposite hands thing too - because the right hemisphere was bigger than the left hemisphere (of his brain) in some activities, he was right-side dominant, and in others, left-side dominant.

it could just be an idiosyncratic uniqueness you possess rather than something wrong ;)

I still prefer to have the fork in my right hand, now days it doesn't make any difference unless your at a formal dinner, its an old school habit which was needed when meat for much dryer and firmer to cut which is why the knife was on the right hand.

But i am right handed but i screw things with my left hand!