I feed Instinct Ultimate Protein Chicken dry and Weruva Meowionaire wet food. Feeding only wet food with 3 cats is too expensive for my budget currently, so we do a mix.
One of the 3 has vomiting issues that were daily with wet food, and it was trial and error until I found a dry food that didn't make him puke every other day.
I have microchip food bowls so each cat gets the right amount. Vomit machine eats 1/4-1/2 cup of Instinct daily and a tablespoon of Weruva wet food. The other 2 each get 1/8 cup of Instinct per day and each get half a can of Weruva in the morning and evening. So I go through 2.5 cans of Weruva a day and 1/2-3/4 cup of Instinct.
Also, the Instinct Ultimate makes their fur really shiny. I noticed during a food shortage when I switched to Tikki Cat Herring/Chicken dry that their coats dulled, and 2 months later when I was able to get Instinct again they got shiny. The Tikki Cat did not cause vomit machine to puke, but I like the Instinct better.
They have 2 fountains that need refilled frequently, so I'm assuming their water intake is good.
I have polycystic ovary syndrome PCOS not Endo, but I share some of the pain. It caused me to miss so much school that I was at serious risk of being held back despite having high grades in high school. As an adult, I frequently use all my sick days just to cope. Last year my new gynocologist finally took me seriously and realized that I was not just over exaggerating. Since I had very high blood pressure on the combo pill, we decided to try the IUD instead ... I had it placed 3 times! Each time, within a week or two, my body expelled the IUD on it's own.
Anyway, we gave up on the IUD because it wasn't working. Instead she put me on Slynd (drospirenone) a progestin only pill. For some people it stops menstruation completely, and I was lucky enough to be one. After 19 years of pain, I've finally had 9 months of feeling great! I don't have those stabbing knife pains in the middle of the month when I would get cysts. I no longer get anemic from blood loss or have 7-13 day periods with cramps that feel like I'm in labor. I don't have a period at all!
I know that I've read stories of women with Endo who say they've had success using birth control to stop their cycle which stops the Endo tissue from growing each month.
The slynd is prohibitively expensive if insurance doesn't cover it. However, there's another progestin only pill that is coming out next year in the US that will be over the counter and supposedly affordable. That med is called Opill (norgestrel).
Sorry for the wall of text. I just want you to know that I feel for you and you have my deepest sympathy. It sucks trying to get a diagnosis for reproductive pain, and please don't ever let them wear you down. The pain is not normal and someone should be doing something for you about it! I hope your upcoming appointment goes well and you get some relief soon.