I wasn't going to but this upsets me ...
Okay love, I have no idea the archaic measurement of a stone but I know what I see from the pictures. You are severely underweight. Someone else hinted on that you might have BDD or anorexia which would be entirely understandable considering events in your life. You need therapy for that and/or at least a certified nutritionalist. You aren't in a healthy state currently: like a pendulum swinging from one extreme to the other. I hope you get well and the help needed to gain as well as be able to see your true form in its healthy shape.
Also if this 'trainer' is enabling this...fire him immediately. As in, yesterday. I want him gone. A nutritionalist would be good to have currently. You've already lost the weight. Now you need to work on eating right and knowing what is healthy for you. Which it seems you already know this isn't right.
Vulnerability is a feast. Don't let them see, don't let them see.