I would pick the J pouch over the stoma every time; although, prior to my J pouch surgery, having my bowel removed and a stoma created, it gave me my life back.
You shouldn't be expected to make such an important and life changing decision within weeks.
I assume your large bowel is all still intact; therefore, can you not ask if it's possible to remove all the troublesome part of the bowel and leave the anus and a rectal stump.
Within the UK, it appears to be normal practice to remove the infected bowel first and create a rectal stump and providing time to recover and adjust to the use of the stoma and bag.
Some patients recover and adapt so well, they choose to keep the stoma and bag.
I adapted well and I wished I had my bowel removed and the stoma created years earlier but I still opted for the j pouch years later.
So, if I can have a Stoma for so long then a J pouch; this maybe a route you could explore, maybe 12 months later, which would given you sufficient time to recover and also experience day to day life with a stoma.
I only waited so long years, as it was thought I was suffering from Crohn's rather than UC, eventually Doctors decided I didn't suffer from Crohns after all and I was able to have a J pouch, which was the best decision I've ever made; life was good with a stoma; life's better with a J pouch.