I’m not a Dr but I know enough about this issue to offer an opinion, I do believe that masturbating very quickly like this will kind of ‘train’ you to always get off very quickly, and later on when you want to have sex with a girl, it’s quite likely you’ll ejaculate way too quickly & she probably won’t be too happy about it. What you need to do when mastubating is slow down, when you feel like you’re close to cumming, stop, take a few breaths, let that feeling subside, then resume. After several times you can allow yourself to get off, but each time you masturbate, keep doing this start-stop technique. Eventually you’ll be able to hold off much longer...