If I were in your shoes and could not tolerate mesalamines, yet did not want to try biologics just yet, these are the things that I would try:
1. psyllium seed powder
2. probiotics, and if you are interested, make your own kefir. Trillions of probiotics in a cup full, cheap and sooo easy to make. I cannot believe more uc'ers dont make and drink their own kefir
3. making your own retention enemas, such as the vit e enema, kefir grain enema, heck maybe even a vsl3 enema
4. fecal transplant at home
5. bee pollen, propolis, boswellia, curcumin, clay(just saw a post about this)
6. diet mod for sure, keep a food diary.
now you may or may not have tried any or all of the above, i was just brainstorming for ideas, trying to put myself in your shoes.
** hugs** hope you feel better, uc sucks.