The average weight is about 135lbs. 120lbs and lower is considered underweight for that height, while 165lbs is considered overweight. There are many helpful tools online that can help you find this information as well as calculate your BMI.
You sound quite overweight to me. Your weight for that height should be 125-170, definitely not past the 200 mark. Talk to your doctor about a good weight loss plan. that's definatly overweight. im 12 and weigh 10 stone and are 5ft 4" tall, and im very overweight
According to About.com:Pediatrics BMI calculator, for your height and weight, you are in the 65th percentile for your age. Any child between the 5th and 85th percentile for their age is considered healthy. So in other words, no you are not overweight.