Alfredo,
First, my young friend, never give up on your dreams to fly. Maybe you will have to post-pone your flying for a while, but never give up. I loved airplanes also from a young age, but I was not able to start flying until I was 40 years old. No matter, I'm still having a great time. RC is a sport for all ages. Many people at my club are over 65 years old, and we still laugh and have fun like kids.
Try to lighten your helicopter as much as you can with out losing strength in critical areas. All decals and decorations must go! Trim away un-necessary body work. Think twice, cut once. You may be able to find a battery that is the correct voltage, but smaller in size. You will have shorter flights, but go higher! The battery is no doubt the heaviest part of your craft. Good Luck.
Never Give Up. Jack.... aka 3wire