Thanks for the messages guys, I really appreciate it. I'm in Sydney now, and am feeling... not so great. Incredibly tired. Have struggled during the day.
Calorie/ kilojoule counting doesn't look like it's going to work so well here. It's a lot more freeform and mum looked at me like I'd lost my mind when I suggested weighing ingredients (to be fair, she asked how much of something to use in a recipe, and I said "the recipe says 100g. Why don't you weigh it?" which I don't think is unreasonable, particularly as she asked me to buy her scales like mine, and I did). She keeps handing me things to try that I can't get/ afford in the UK- which is good for lots of reasons, but nutritionally not so ideal.
So... let's see. Today (after I landed, so after 6am AEST- which is 9 hours ahead of British summer time. I'm starting at that point because I was more in control of my food at that point and also because from there on my time zone is/ will be stable) I've had half a cup of tea with low fat milk (it was vile, don't know why), a teaspoonful of the porridge mum made (she has a new technique and wanted to show me, I ate breakfast on the plane), half a piece of cake and some hokey-pokey ice cream ("you have to try this... oh, we have this ice cream that you can't get in England and I just happen to know you adore, we're all having it with the cake"), a sandwich with lamb and a minty sort of jam for lamb, a tiny portion of chicken mum wanted me to try, a smallish portion of a salad mum wanted me to try (spinach, feta, pumpkin, can't remember what if anything else), some water, and mum's take on this recipe (I didn't have a chance to take notes and I'm not sure mum would've been too keen on the idea):
Exercise wise, I've played with Dita (the family dog) who definitely remembers me

Took her for a walk (this area is hilly), have run around the house with her a lot, etc. No idea on distances, but this house is big and I've probably done at least 5, maybe even more than 10 laps of it.
Exercise will hopefully help alleviate my lack of control diet wise, and hopefully it'll settle down and become more/ mostly healthy.
Currently drinking lemon and ginger tea as a night cap (need to go shopping with mum for things like night tea) and am about to toddle off to bed.