I work out at the gym 2-3 times a week, have a high protein diet, walk everywhere I can, never use lifts (elevators?). I'm 55kilos upper body muscle strength has dropped, as I use weights at the gym I have noticed my weight lift tolerance is dropping, and I love it

. Some of the guys even take weights off machine for me as they are too heavy, love it again

My daily calorie intake is about 2000. But I'm fortunate to be genetically slightly built, if I was a guy I would get sand kicked in my face.

I think you just have to keep at it . Biotin is also very high in egg whites, and in multi-vitamin tablets (Vit H)
Keep on going, you will get there you just need to keep motivated. Find a cute skirt or top you would really like and aim to wear it
Hugs
Cindy