While losing weight seems to be your #1 priority, it sounds like finding an apartment or a house that is on one level so you would not have to struggle to use the loo would be of the utmost importance.

There are exercise machines like bicycle pedals that you can use for upper body exercise. They will help you burn calories. Here are two examples (one expensive, one not). http://www.a3bs.com/380-E4-Upper-Bod...FUKd4AodFTsA-Q and http://www.sears.com/shc/s/p_10153_1...e=35-1917412-2

it sounds like you are managing the best you can and are a productive person and an asset to your community despite your disabilities. i also suffer from a lot of food intolerances and they complicate life greatly. i have taken to eating hummus on toast (you would have to have gluten free bread), which i like a lot. here in the states, it comes in many different flavors. of course, you can add your own toppings such as olives, pepper, paprika, sumac or a drizzle of olive oil. i avoid chips (french fries here in the states) as much as possible and instead like to bake potatos in the microwave, shake on some seasoning and drizzle extra virgin olive oil on top. I also do this with yams / sweet potatos. all the best to you!