Hi Irene - welcome to Susan's!
I would agree with the previous posts, you are already on the lower end for weight and your size (I am 174 cm). Losing more weight may also deprive you of some of the strength your body needs once the hormones are changing. You will also need some fat to build up in the right places for a more feminine body structure. Losing more weight will not help gain this, the change in hormones will help. Once your hormone levels are right, your body will know how to change. Two things to keep in mind: It is not an instant change. Compare this to a girls puberty where breasts develop over the course of several month to a few years.
You can look into some exercises, if you look for "feminization exercise" on youtube, you will find a bunch of videos targeting mtf. This might be the better choice.
Good luck, hugs Sarah