didn't read the top article.. but keep in mind -> there are different types of strokes, not just forward. but correction, sweep, draws.. etc. you can look those up or try and look up paddling technique.
but I"ll give you a start.
I did the same thing as I'm sure everyone does when they start kayaking. A good forward stroke in the water is a little more vertical than what your used to. I do about 50-60 degrees of an angle from the level of the water and my paddle shaft when doing a forward stroke. You want to initiate at the feet and stop and pull out the stroke before you get to your hips. When you take the paddle blade out it should be a quick movement and you should feel a kind of 'pop' as it bounces and flexes. Your probably spinning because your dragging the blade or doing too much of a stroke. keep the paddle blade relatively close to the boat, the further away, the more your likely to turn.
Correction strokes, think of your boat in this way.. the bow as A the middle as B and the stern as C.. a forward stroke is close to the boat, somewhat vertical, and goes from A to B.. To do correction strokes or a "stern draw", you initiate at B and go to C with the angle of the shaft more horizontal and keeping the blade about a foot further away than the distance of your forward stroke. B to C stroke on the right side will spin or 'correct' you by turning the bow to the left. B to C on the left side will turn the bow to the right.
Now get out there and practice, but read up on technique or get a White Water paddler to show you the ropes.