Singerboy,
That bulge you get is temporary. Call it a doughnut, for lack of a better description. It doesn't hurt anything. But it's caused by "Dry Jelking," meaning dragging the skin along with a lot of squeezing, from the root towards the head.
Wet jelking is what you probably want to do more of, at least to begin with. That's when your cock is semi-hard, and well lubricated, and you jelk straight out from your body, hand over hand, like milking.
The dry jelking works to thicked the penis, while the wer jelking works to improve blood flow. Both will lengthen it a little. But to really lengthen it, you have to learn how to stretch it. Do it too hard, or too long, and it will actually shorten for awhile, caused by a damage reaction, that causes the ligaments to twist up and shorten to protect them.
So lengthening is part patience and part "feel," to know how hard and no harder. It will take a couple of months to catch on. Keep a ruler and check on it after 30 minutes. each time you start again, it should be shorter than when you finished the last time, but gradually longer than what you began with.