Why I need to lose 10 kilograms

I'm 20 at university and weigh 70 kilograms. In no way am I overweight. I have an hourglass figure, small waist, enormous boobs and butt.
Why am I here?
Well, I did get called fat at my university by a few size 4 blonde women, let's put it like that.

Now yes, I realise I don't need to listen to them. And that I should be content, and all of that.
But I can lose weight and still look healthy, and truthfully I want to do it, for the shock factor of these few people.
Usually, I don't get upset by what people say, but this time it was actually hurtful. So instead of throwing a pity party, I'm going to lose some weight and feel fab.

So yes, I am aiming to be 60 kilograms once again, which I was when I was 17. Yes, I'll be looking at toning my body as well, so I suppose I am not too fussed if I don't lose 10 kilograms. I'd more like to drop a dress size, and have a smaller waist and what not.

I tend to get too busy in my life, or have anxiety over going to the gym or any gym classes, so I put off exercise and a healthy diet. And I guess, that's why every time I start diet, I fail.
I know that once I start and lose the first 4 kilograms, I will be confident enough to keep going and feel good about myself.

I think that is my sob story so far.