Welcome to the forum.
Glad you found us.
I am so sorry about your recent UC diagnosis. UC is a tough disease to deal with.
Sounds like you're on quite a roller-coaster ride of stress and anxiety, as you probably know it's so important to try and get both under control with UC.
Did you doc take any biopsies?
You mention bacterial infection, did they do any stool tests?
Here's a good website that tells you the differences between UC and Crohns:
http://www.columbia-stmarys.org/Crohn_vs_Ulcerative_Colitis
As to your questions:
1) They can do a Prometheus test - but I don't know about its accuracy. It's a question of symptoms and what they see on the colonoscopy, and of course, having a good GI.
2) Excessive fatigue is normal with IBD.
Has your doc checked your blood serum levels of Vitamin D3 and B12?
3) Make sure you do the prednisone weaning slowly.
4) Don't be so hard on yourself. YOu're going through a rough time, and you need to go easy on yourself so you can heal. As far as diet is concerned, are you sure the one you detailed agrees with you? I know personally, I couldn't handle half of what you are eating. Many of us have problems with gluten and dairy. I note you mentioned having yogurt causing major problems for you.
5) Personally I don't agree with low residue, partially because it really doesnt' address all the problems.
Many of us here have done SCD, Paleo or Gaps. IMO, Paleo is the best one because it's an anti-inflammatory diet, but you'll need to research all of them to see which fits your needs best.
Now I have some questions for you:
Are you on any supplements?
Taking any probiotics - these are very important.
There are things IMO that you can control, which will have a direct impact on
your disease, the symptoms you experience and their severity.
I was able to control my UC into remission through various
supplements, probiotics, diet modification, and LDN , low dose
naltrexone.
For more info on the protocol which has put me into remission,
please go to this link: https://www.healingwell.com/community/default.aspx?f=38&m=1666318 , and look at the 11th post.
I hope you feel better and let us know how we can help
you.