Just told that I have a “thickened gallbladder wall” at Emergency Room, but sent home

Hello, first time poster seeking advice. I have been having pain on my right side, but I also suspect I have endometriosis due to the painful nature of my periods and gastrointestinal issues. I am on my period right now and I went to the emergency room, I had been having pain specifically after eating on my right side. They gave me a CT scan, and found I had an inflamed stomach lining, diverticulosis, and a large gallbladder. They gave me an ultrasound on all of my gallbladder, liver, pancreas, and kidneys, and I was told that everything was normal except my gallbladder had a “thickened” lining. No fluid, no stones, and they did not seem very concerned but told me to follow up with a GI doctor. I made an appointment, but it isn’t available until the 23rd of this month. Is that going to be alright? Will something bad happen if I don’t get some kind of treatment before then? What should I do to ease my pain before my appointment? I am a 27 year old female.