Do I need to exercise while being anorexic already?

Alex

I’m 43kg and honestly feel so ugly compared other girls my age (16)

They all talk about going to fitness places and training in the morning and it being awful but they train for the body

And honestly feels like shit

I’m already so small and have a BMI on 16.8 and I’m trying to get back some weight to be at least be on average weight but with all these girls at my class always complaining to be about training it makes me reconsider getting weight

Do I really need to exercise to get thinner and better or any other suggestions?