[Kurn, son of Mogh]

First of all - learn the math of the game.

You said:

I have a suited Ax or Kx, and I flop two of the same suit. Probably 5 out of 8 times, that suit doesn't land on the river

That means that the flush card *does* come in 3 of 8 times, or 37.5% of the time. Since the odds against making your flush by the river is 1.91:1 or 34.6% of the time, you are actually observing the flush come in more often than it should.

You're never going to learn to play well until you learn the basic math.