Chris, my initial thoughts are to do whatever you can to save your j pouch. This might entail having a consultation with a doctor who has lots of experience in dealing with pouch problems. Once your j pouch is removed and your bottom sewn shut, there is no going back. If you would list the problems you are having, others on this forum could offer suggestions.
In my case, recurrent high grade dysplasia in the anal cuff and a malignant polyp made removal of my j pouch necessary. I strongly did not want an end ileostomy with its associated issues and researched the two alternative procedures that avoid the need for an external bag: the k pouch and the BCIR. I selected the BCIR and have had excellent results. Although my surgeon was not able to use my j pouch in constructing the BCIR, there was sufficient small intestine to make the BCIR (less than 3 feet). Although I lost 40 pounds after the operation, I have put most of it back on and now have to lose a few pounds after the holidays. I have no issues with weakness and dehydration and I can participate in all the physical activities I enjoy. I am told that I have sufficient small intestine left to make another pouch, in the very unlikely event that becomes necessary. Please feel free to send me a PM if you have any question, and best of luck to you.
Bill