Hi, poor you!
I would deal with one thing at a time.
For Down below I would see a vulval dermatologist, to see if there is anything to be diagnosed etc.
Just use YES products or hydromol as a barrier cream.
I use organic cotton panti liners and change them at least twice a day in this weather as sweat and vaginal secretions can irritate the skin.
Sounds like the Mona Lisa worked for you, until the ovestin? maybe try that again?
Try ginger for nausea, it worked for me when I started HRT, and eat little and often.
Speak to your GP about acid reflux, antacids can help such a ranatadine in the short term .
Take a good probiotic , that can help with upset tummy.
Stress can play a major part and make everything worse.
Maybe try some some counselling, mindfulness or can you speak to a friend?
I am not sure about the oestrogel causing inflammation down below, or wether that is a coincidence. Anyway one thing at a time, otherwise you wont know what is working and what isn't.
I do hope you feel better soon.
Pepperminty x