I have smpathy with your problem of needing to sit next to the toilet.
I had the exact same problem with BA some years ago who refused to allocate my disabled father a seat next to the toilet. The whole purpose was to allow him to be able to swing round into the toilet with my help and thus avoid urinating into a bottle and me carrying it down the aisle.
Despite many phone calls i couldnt get a resolution and switched to AA who provided an excellent service to the disabled.

My parents, both in their early eighties have decided they want me to take them to San Francisco for what will probably be their last major foreign holiday. BA are the logical choice, they want to travel WTP but the seating is different depending on the configuration of the plane with the risk that if the plane is high J there are no seats next to the toilets.

Sadly this means we may have to fly United or even NZ and drive up from LAX.