Mancunianma I also live alone and have been ill this winter. As it happens, I've developed a nasty illness that means that every little bug lays me low for several weeks...
So I have an emergency plan, which is to always ensure that I've got enough food stored to last me for at least a couple of weeks, then, if I can't get out, I know that I can have something to eat; some tins of soup, tuna and beans, a couple of sliced loaves in the freezer, some eggs, a packet of porridge oats, cornflakes, some baking potatoes, cheese, butter and milk will allow you to keep yourself going, even if (like me last January) you live on soup, porridge and baked potatoes & cheese for a while...! 
I also started to order an online delivery of groceries every six weeks or so, so that if the weather's icy or I'm not well enough to get out, I can do this with confidence, and keep myself stocked up.
The other thing that I've done is to register with my doctor online, so that I can order repeat prescriptions and then the chemist will deliver them, meaning that I don't worry about running out.
These are small things, but they mean that if I'm confined to the house, at least I know that I can eat and that my medication won't run out, which is a weight off my mind.
I've found that this 'forward planning' has given me peace of mind, and I don't fear being ill as much as I used to - I hope that you can put your own plan in place so that you will feel the same 