There is something wrong with your pouch or you wouldn't be in such hell. You need to see your GI or surgeon and get their help. Have you tried calmoseptine for your butt burn? It is hard to figure out what to eat and when. Have you tried Imodium and/or metamucil? Is there any other position that you can do, where you work, that doesn't require all of the pressure on your j-pouch? I know asking about that is usually easier said than done.
I don't eat much meat anymore but when I do it's chicken or ground beef. I wish I liked fish but have a greater aversion to it than I did before my surgeries. Have you tried yogurt? I also like smoothies with a protein powder, almond milk blended with some fruits and veggies. I didn't think we should automatically do enemas on a daily basis but there are some of us that need to. I forget the name of the guy here that does one daily and he has no problems. I think they are easier to do with my bidet.
I hope you can get into your doctor quickly. If the front office won't get you in soon then ask to talk to your doctor's nurse. By explaining to him/her how bad things are they usually can get you in right away. Most doctors have open times in their schedules for acute patients needs - like yours.
You are going to get better and I hope it will be soon.