Let’s start from the boggling.
First, forget every thing you had learned about edging (not saying that the others opinions are wrong, I just think you need to have a fresh start.
Start by masturbating as usual. You need to be relaxed and focused on what going on in your body. And the most important thing, FORGET about kegel. Actually, you should forget about your BC muscle and try to keep it relaxed without any contraction.
As you continue masturbating, you can feel the sensations build up in your penis. With every stroke you’ll be closer to the PONR, and for the ejaculation. Now you need to identify the feelings that you have just before this point. You need to practice, if you don’t already know how it feels like. You can practice by normal masturbation, but with slow strokes. This way, you can observe all the stages toward the PONR.
(I describe the feelings that precede the PONR as a tingling sensation at the base, with a hard urge to contract the BC muscle, regardless of how hard you try not to.)
It seems that the problem with you is that you reach the PONR then stop stroking, where you should stop before this point in order to stop the ejaculation process. As a start, when you identify the stage that preceding the PONR STOP completely for a couple of seconds. And REMEMBER, keep your BC relaxed and don’t do any kegels. Then resume stroking in slow motion and light force. You can go for this for some time, depending on your conditioning level. Then, again, stop if you reach the point before PONR. And repeat as long as you can or want. Then let it go if you want.
Hope this was clear enough, and helped you.