You have to eat and drink, op, and it sounds as though you haven't gone over the top - as you say, you've only been out once in the last month apart from work. Your work is important too so you must keep your energy levels up.
I take the points people have made about 'free from' milk, my cousin has it. My milkman still brings milk, other things are not available but there is milk, maybe not the type you would normally have but it goes down the same way.
I noted there is now a shortage of eggs, butter and spreads. I have ordered from milkman to leave on Tuesday but anything could happen between now and then, I was expecting some this morning but had an email telling me 'unforeseen circumstances' prevented the delivery of them and I was refunded. I live in hope for Tuesday.
In these times with such shortages we'll find ourselves adapting and eating things that we wouldn't normally. For example, using evaporated milk instead of cream on tinned fruit rather than fresh. I used to have that as a child at home and for school dinners. Being less fussy about the bread you eat - if all you can find is a white sliced, so be it, it won't harm most of us (those who must have gluten free are different). I have some long life part baked baguettes which is very useful - also no hardship because I like them anyway. Some people bake their own bread but currently there is a shortage of ingredients.
If we are open to doing something different it will make life easier.
It's funny you saying the Co-op is expensive op, I've always got amazing bargains in my local Co-ops and used to come home feeling very pleased. I suppose they vary according to where you are. If you use Co-op online delivery, that is more expensive than going into the shop. Any
way they aren't functioning at present, I had an order booked for one evening this week and it just didn't turn up.
You're doing OK op, good for you and well done for work too. Just avoid Alpro and the like from now on.