So I'm 15...and I really really really want to loose weight but i hate to...

sorry...running is the best way. JUST DO IT!

At your age its not really healthy to lose weight, unless your doctor is telling you that you need to. However, try going to the gym. Try weights and rowing machine. If not, consult your GP and ask their advice.

Honestly, the only healthy way is to exercise. But running won't really do anything for your arms or stomach.
Stretch your stomach out by doing a back bend before you try any exercises. If you don't, the muscle will build on top of the fat and you could look bigger than you are.
Try laying on your back and holding your feet up off the ground, or even try a sitting position with your legs while laying on your back.
With your arms, it's easy, you can even lay down in bed and do this. Hold your arm up off the ground and use a weight, or even a water bottle and just pump your arm up and down.

The other thing you can try is eating a small meal, every couple hours and not a 3 big meals a day. And DO NOT eat atleast 3 hours before you sleep, it's too hard to work off those calories.
Also, make sure you sleep well enough. You burn more calories sleeping than you do watching tv.