Hi and thanks for writing in. It sounds like you are getting pretty frustrated being called names and with people comparing body weights. At 15, your body is still developing (the same as for other guys your age). Adolescence is a time when people compare themselves with others and there is a whole stack of pressure to conform or be the same. What is important though is who you are on the inside, and to remember that we all come in different shapes and sizes. I can see that it's hurtful when people call you names, so it would be helpful if you can talk about this with a trusted friend or adult.

If you want to "buff up" I would recommend you join a gym and get some professional instruction. An instructor can design a fitness plan that suits you, taking into consideration your height, and that your body is still growing. I reckon you will find that your self-confidence will increase as you begin to feel better about who you are.

If you have feelings or thoughts of killing yourself it is really important that you speak with a trusted adult. You could ring a helpline (see below), see your doctor or talk with someone in your family. I understand it could be difficult because you are shy but I would encourage you to talk through your feelings. You could show them what you've written here as a way to start talking about these things.

I hope this helps. Take care.