This sounds very hard, @SadieM1210. Do you think you are producing an unusually large amount of gas, or just having lots of pain with a fairly normal amount of gas? My gas used to be very noisy, too (once during a job interview!), but that has been much quieter for many years now.
It’s important to work out a way for you to poop on the toilet, and there’s nothing to be embarrassed about. It’s essential that your doctors know exactly what’s going on. One possibility is pelvic floor dysfunction, which could be relieved with pelvic floor physical therapy and/or biofeedback. It’s also possible that exploring more positions on the toilet, especially bending forward, may help. Another possibility is that there’s something structurally wrong with your J-pouch, and that would need time and attention to work out. Until you are pooping without difficulty it will be hard to keep things from backing up and causing pain.