Most Helpful Guy
I don't think your weight is an issue, just by the way you described things. At 14, a lot of guys aren't mature enough to go after someone who isn't really flirty and a porn star in training. You'll find the right guy, it will just take some time and you may have to go outside of school to do it. Remember to be choosy! Having not dated before, you probably feel desperate, but keep your standards high.
Most Helpful Girl
I didn't have a boyfriend all throughout middle and high school, so I know what it's like to so badly crave a solid relationship like all your friends seem to have done. Just know that there are so many other girls in your same position. You are still so young and have so much time to find someone. Most high school relationships don't last anyway, although I know it's still a fun thing to experience.
Try to be more approachable. Have a sweet/friendly/open attitude, make sure to smile, etc. If you're already doing all that, then I don't know... Maybe try to spark a conversation with a guy who's quiet or shy?
Another thing you could do, if you haven't already, is get more involved. One of my biggest regrets is not sticking with doing cross country after freshman year. It's nice to be a apart of something, and have an opportunity to meet a bunch of people.
Nice job on your awesome GPA. :)