1 & 2. Yes, exhaustion is a huge problem for some. It's even a problem for me while I'm in remission; I just don't have much energy. I just make sure I get enough sleep and take naps in the afternoon. Have you had your blood levels checked? You may be exhausted because you're anemic.
Luckily I've flared badly in the summer so far, otherwise I'd have no idea how to handle classes. Just try to do your best and don't stress yourself out. Sorry I can't give any more advice than that. When you go to college, register with your college's disability services; they'll help with housing, talking to professors, etc.
3. Lack of bleeding usually does signal remission. Remission and the timing of remission different for different people, but generally it's being close to what you were pre-UC. For me, that means no blood, a couple BMs per day, no urgency, etc.
4. Don't push yourself to exercise too much if you're feeling weak and flaring. On a good day, you could try a little cardio and/or weights. And then move on up to your regular routine once you reach remission.
5. It's hard to deal with emotionally for sure. I had this disease for almost a year and half and some days still have time accepting it. I have not told any of my friends about it; they just know I have a chronic autoimmune disease. I really don't feel like going into details about this disease for obvious reasons. Don't worry about what your coaches will think or letting down your team--you have to take care of your health first!
There have been studies that show fish oil and especially probiotics can help with UC symptoms, so they're definitely worth a shot. What brand of probiotics are you on? I'm not completely sure about digestive enzymes or prebiotics (maybe someone else will chime in). I've refused steroids as well, but definitely ask about rectal meds. I know that they're embarrassing, but they do help!
Female, Age 20
9 Asacol, Rowasa, 1000 mg Canasa, Proctofoam, Rifaximin 2/day
Digestive Advantage (Crohn's & Colitis), 1 Florastor, 50 mg 6MP, 1 Primadophilus reuteri, Remicade (6 infusions), 2.4 g Lialda, Forvia, 6 Colazal, 1 Anucort, Culturelle, Fish Oil, Calcium/Vit D supplement, 20 mg Prozac, VSL #3 DS, Turmeric