Try not to feel too overwhelmed. Keep it easy to begin with and build up.
Jacket potato, something on toast, sausage & mash, tin potatoes with cheese & beans.
These can easily be built on when you feel brave enough - sausage casserole (packet mix, sausages & a tin of beans) to go on the jacket, or a chilli or curry.
Put some chicken or fish & veg with the tin potatoes etc x