So we are all insecure about weight. So don't feel bad. But the right weight for you depends a lot on how tall you are (also you can carry more pounds or kgs if you're toned by exercise) But I can't imagine even 43 KGs being overweight unless you're under 5 feet tall (152 cms) since it's only about 95 pounds. So I think you should stop worrying.

I'm sorry I'm unable to be all polite about this, but this is a serious problem. If you see yourself in a certain way and there is nothing a person can say to change your mind, that is a problem, in the mind! So you should really seek help from someone who's not your age and knows a thing or two about life, because girl, you're underweight.
Good luck.

You're probably underweight, unless you are really short, but even then you'd be of normal weight not fat. I suggest that you talk to someone you trust about this insecurity as it is not healthy.

No. You're not. You're perfectly fine the way you are. Honestly, you need to work on your self-esteem, before it's too late. Pleaseeeee just think about talking to someone about this... You're the perfect size, you're you, and you need to learn to love that.

You need not to feel insecure. There are lots of fun activities you can do. You may visit http://www.nyccosmeticdermatology.com/lipo-zeltiq.htm for a no surgery fat loss.