Is it one leg that is in plaster or both? You only need to be non-weight bearing on the one in plaster, I cant think of anything that you would need *both* to be non weight bearing for, although Im open to suggestions - in fact it's a good thing to keep as mobile as possible to maintain a good blood flow for repair, avoiding clotting and to guard against osteoporotic problems. As well as to keep your calorie usage up!
Also if you can't use your legs at all they have to provide you with a carer to wash and dress, toilet, prepare your food for you and other such essentials for short period each day. They may also provide you with a wheelchair to help you around if its going to be like this for some time. Also if there are stairs to your toilet and you cant use both legs you need a commode. You can hire all this stuff if they dont provide it. When I was a med student I got run over and almost lost one leg entirely, I had transplants, bone & skin grafts, screws, plates, the works, spent 4 months in hospital, six in a wheelchair - so I got to know the ins and outs!
It will seem really really tough now and you have my sympathy but I promise in a while things will look up.
Most stuff is pretty easy to do on one leg when you get used to it
I know the plaster is heavy but seriously you do get used to it and you will soon be bored out of your mind at sitting down all day!
I agree with the posts above, get your OH to prep you a little easy-area where you have the necessities to hand - kettle, toaster, fruit bowl - Even a mini fridge maybe!
You could plan what meals you want the next few days and what you will need and he could leave all the ingredients/utensils for the day nearby when he leaves in the morning and you could prep it yourself. Or maybe get him to chuck it in a slow cooker for you or make things that can be eaten cold, although Im sure within a week you'll be hopping along in the kitchen no problem!
Also agree on the weight of the cast/crutches - they're not going to change so you can still compare week to week
Good luck, and get well soon! x