How can I lose fat without loosing more weight?

If your already underweight I suggest you stop where you are and do NOT try to lose any more. You can’t lose fat off your body and not lose weight at the same time - virtually impossible. Also, if your ribs are very visible that’s not a good sign. I think you need to gain weight before you become ill!

I understand what you mean, you need to ‘tone up’ so do not stop eating or anything because that will just make you slowly go annorexic. go to a gym, or focus on weight lifting to tone your muscles up. if you eat heaps of fatty foods, that could be why. but dont go on some crazy diet lol as you are pretty skinny already. toning up is what you want I think.