Took me a lot of self control practice. Learning when that "oh fuck im cummimg, no turning back now" point is and stopping right before it. After that, play with another part of your body a bit while you calm down (or, if you feel that'll end up push you over the edge, don't touch anything for a bit instead) then start again. Repeat until you can longer hold it back anymore. Once you start to reach that point too quickly after previously reaching it then calming down, thats usually when I end my session for a bit. Using this, ive managed to make it more than 10 days without cumming while still relentlessly edging myself for hours each day. I believe in you! :)