caravan in garden HELP PLEASE - Public forum - Planning Advisory Service (PAS)

Could  someone please please help   (I'm pulling my hair out) had sleepless nights

I wish to put a American 5th wheel trailer  (towable) in my rear garden 28ft long  8ft wide....  This is to house my elderly father who cannot make the stairs anymore.

I called council who said as long as its ancillary it does not need planning permission...  (I have ordered the van),

I then got a call saying that I need full planning permission or notification of planned development. (If I do not get it the van will be removed ?)   

I explained it is to house my father he will be eating with me I do all his meals and washing etc etc  its basically somewhere to sleep and use bathroom facilities.

 I explained I live in a very old house and the stairs are to steep for him I cannot fit a stair lift due to stairs  He is in ill health and cannot make the stairs etc etc.

I live in quite a rural area the site would over look woods (paddock) and my neighbour could not see caravan unless they jumped up and down to look over fence.

It is not in view of the road and does not interfere with anyone.  No Covenants on the land very large back garden.   The council said that it maybe an eyesore to persons  (I have a farm at the rear off me with farm machinery  and various barns behind my back fence eyesore ? I do not think so)....

I thought under section 55 town and planning act I can have this it is ancillary and incidential to the main house, just to house an elderly gentlemen so he can sleep.

I advised the council that currently he is sleeping on my floor and using bucket for facilities I'm trying to make him as comfortable as possible.  The insisted that I need planning 

  HELP PLEASE>>>>     All im trying to do is keep him home with me......  HELP