A couple of things that might be a help. When I was having chemo the smell of food put me off, but I got some weetabix, which I still have now. It has no smell to me, and I put a little canderel on it and some milk. It can be eaten any time I think and so if you suddenly realize you have had very little to eat, it gives you something and the milk is good for bones etc. Also if you have to take any tablets that need you to eat food first, again it is an easy go to food, so a useful back up to keep in the cupboard.
Then is there any particular fruit or food that you enjoy or see as a treat normally? I would suggest that you choose some comfort food and have that available to tempt you. sometimes old favourites can be cheering, so perhaps a lovely old bread and butter pudding, or perhaps make up a stew or some mince or curry and then put into small portions and freeze them separately. That way you are not forcing yourself to eat them on the day you make them - although hopefully they might tempt you to enjoy them - but you will have something in and quickly available at any time.
Again I rarely buy takeaway things but it is worth having say the local chinese or pizza menus so that you could occasionally have something brought to you when you feel like it. If you can see this as just a temporary problem and not something to worry about too much , I think as hopefully your problems and worries lessen you will get back to your old ways. Could you also possibly meet with a friend either for a lunch at a cafe or perhaps a church meeting lunch. Wishing you all the best