Disabled dieting

Hi I am just starting out so somewhat still finding my way around the site. I am 44 years old and upto 2 years ago was reasonably fit and healthy but unfortunately I was struck down with a neurological condition called Transverse Myelitis which comes under the umbrella of Multiple Schlerosis. I use two crutches to walk or sometimes a wheelchair. I have nerve damage down the left side of my body and in the last 2 years have gained 2 stone so I think it's time I done something about it.