I am limited to 1/4 cup at every "meal" and can usually but not always, eat it all. I make sure to wait at least two hours in between every 1/4 cup and also definitely wait 1/2 an hour to drink after. I have never seen this be anything but an absolute rule as it pushes your food through to fast . I also set my phone timer for every 10 minutes and drink so that I don't fall behind.
It is important to work on getting that Protein so that your body does not turn to your muscle to burn instead of your fat. That is another reason low carbs is important. Finding a Protein drink you can drink once a day is pretty key and I myself find I can manage one if I mix two scoops of chocolate with a cup of Decaf and ice and blend. The Unjuy chicken Soup has also been a lifesaver - savory and really just lie broth to me- I do add 12 ounces of Water instead of 8 or it is just too salty.
Certainly you will lose when you are eating so little but eventually your body will go ointo starvatio mode and stop losing and this is the time to get theprinciples like protein and Water in place. For the first couple of weeks it is not so important but certainly once you are a month out those goals should be met for the best results in the longterm.
The acid inhibitor can really help!
Good luck- I feel for you who are having problems. I kind of grouse about my 32f bougie because my capacity is SO small but I get my protein and water every day without fail.