Hi veglover.

Thing is with protein, is that you need enough for muscle repair and other technical whatnots (I would say I eat below recommended amounts). But as for eating-wise - you need to eat enough to feel satisfied, to not feel hunger. We're all different so you just discover that out for yourself through trail and error. if you need that extra piece of fish to stave off hunger, then better have that than fats.

So, once you have enough and no more, you make up the rest of your calories with fat, and carbs last of all. I eat very low carb (when fat losing) so for me carbs just pop in by default, rather than I include them. Such as carbs in milk, cheese, nuts, etc.

I ate 1/2 a can of drained tuna in water for lunch today, with mayo, olive oil, and herbs added. It fills me up and is tasty, I'll eat the rest a little later.

Me personally, I find hard cheese seems to stall me. And polyols wreaked havoc. I do eat fatty cream cheese - filling!

The aim is to play with your macronutrient percentages so that fat is highest. At least 65%. I use Fatsecret free online.

Also, now that I'm so close to my goal, I have found that physical movement helps a LOT. Notice I don't say exercise.
More housework, short or long walks, gardening, that sort of thing. There is only so low you ought to take your calories, and also your body adjusts so much. I do this only every 3rd day.

As you still have 5 weeks to go, no harm giving it a try for a couple of weeks, see what happens.

Let me know!