Unfortunately, we never really know what to say to kids that can't get their parents to let them have dreads even after all that, other than just stick it out and be glad that your biggest problem right now is not getting to have dreads. Before you know it, you'll be in college and although, while you now would probably finally have the locks you've always wanted, you also suddenly face a bleak future of four or more years of school and then a lifetime of making crappuchinos at StarBucks because you can't find a better job, despite your degree. Now THOSE are problems - so be glad that you're 14 and in high school and still having fun being a kid. And maybe you can strike up some kinda deal with your parents in the mean time, like you'll do a whack of yard work or get good grades or something in exchange for them letting you get dreads. It's crazy that people have such a problem with them, as they are just like braids or any other hair style, but there is unfortunately still a long-standing historic stigma attached to the look, it seems.
You can also now let your parents know that locks CAN be taken out thanks to our Knotty Boy Emergency Dreadlock Removal Kit. They might take more kindly to the idea of dreads if they know you'll be able to take them out without having to shave your head.
Bottom line is, just don't sweat it too much, have fun and see what happens. Dreads are cool, but not really worth getting hung up on if you can't have them - enjoy being a kid while you can. You'll be able to lock those babies up soon enough.