I'm back up to 80kg (176lb).
I did some maths yesterday and in September on average I burnt 9,000kj per day (2151 calories). According to my apple watch, I don't know how accurate that is but it's all I have to go on.
So my deficit set up by the app I was using is possibly too small, it's based on an average burn of 10,000ish (2390 cal) per day.
Feeling very down.