I'm 7 weeks post op and I have had 2 weeks of not shifting much at all and others where it has dropped off, it's not predictable and your body will fight to hold on to what it knows! However, if you think about it rationally, there is no way you are not going to lose with the tiny amount of calories you're consuming.
I've found that the more protein I get in, the more I lose. I was told to aim for 60 - 80g a day and it was hard at first but yesterday I finally managed to get to 90g and this morning another pound off... water, protein, rest, exercise. The magic combo!
Now you're on purees you would try the Danio strained yoghurts - even if you only managed half a pot at a time they have around 14g of protein and are 100 calories, pretty good! Or a one egg omlette with a babybel light - 100 calories and 17g protein... just takes a bit of fiddling and getting used to to find what works best for you.
Keep that chin up, it will happen!
S x