I did a lot of bodybuilding earlier in life, which was at least in part a compensation for my perceived shortcomings. Then I got older and lazier and eventually didn’t give a shit. Of course, I had found a woman who liked my penis the way it was and actually thought I had too many muscles.
Now I’m much more slender than my previous 225, have a significantly bigger dick, and am generally much happier with myself overall. But damn I wish I had discovered PE when I was younger—I was over 40 before I did.
This stuff does work, but it doesn’t work the same way as bodybuilding—at least it didn’t for me. The objective isn’t to force your penis to stretch, it’s gradually and usually gently to encourage it to grow. These are two very different things. Don’t use all your strength pulling and jelqing. The object isn’t to get a stronger dick; it’s to coax it into growth.
Take your time, follow the newbie routine, and be patient. As others have said, clamping is a bad idea at this point. I never clamped but still managed to gain 1” of girth. See how your body responds to the newbie routine. Gradually increase intensity and time, every 2 weeks or so. I started noticing gains after about 2 months.
Nobody can predict how any individual will grow. I think 2” of length gains are on the outside of what’s achievable for most guys. But it’s not unreasonable. And you are very young.