Morning Di, hope your thrush clears up soon - I know the misery of that, for sure
Can I ask what the calculator gives you for a 1lb loss per week? It's just that 1000 cals is awfully low IMO, and rings alarm bells for me. I once spent 6 months eating 1000 cals a day, and I was a
mess by the end of it (visible signs were that my skin and nails were awful, and significant hair loss). I lost 4 stone but gave myself nutrient-deficiency problems as it's actually not easy to get all the nutrition your body needs at that level of food intake. (I'm not trying to scare you, by the way, just saying that there could be issues with it)
What are you averaging at the moment? If you've dropped from about 1800, I wouldn't go lower than 1300 for now and just give it some time to see how things shake out. You may be on the verge of a downward shift for all you know. That seems to be happening to me. For the past 9 days I've been averaging about 1350 cals, and for the first week nothing much happened; now, suddenly, I'm a couple of pounds down just like that.
But it's entirely up to you, of course. If you do decide to go for 1000 cals, I wouldn't do it for long - maybe a couple of months - then take some time to slowly raise your cals back to maintenance so that you reset your metabolism and give your body a bit of a break.
You've been doing so well for so long I'd hate for you to do something drastic because things aren't moving as fast as you'd like, especially as you've had illness issues lately. Cutting calories by that much is harsh on the body and I'd say that right now, making sure you get great nourishment should be the priority.
Anyway, not trying to lecture you hon, just throwing some thoughts out there xx