What could I do?

[NoNoNona]

Christmas Eve, Christmas Day and Boxing Day I will be alone in a hotel room. There is a coffee machine, I get breakfast, but other than that I have no clue. I hate any kind of "Christmas" food other than bread sauce, which I obviously cannot make.
Suggestions please.

So you're looking for food options? Is there a fridge and a kettle? Can you go out at all? I appreciate that a restaurant for christmas dinner might be a bit uncomfortable but takeaway could work? Does the hotel have a restaurant or room service?

I imagine that most takeaway type places would be open Christmas eve and Boxing day, if not on Christmas day. If you need food in the hotel and no other waay to access it I guess you'd need to rely on tins or food that has a long shelf life?

Lovely breads and nice cheeses. Snaffle some butter from the breakfast. In fact (I wouldn't normally but it's an awkward time of year), grab some pastries and whatever from the buffet (hide a knife or bring one with you for the bread and cheese), and keep in your room aswell. Buy crisps, nuts and snacks. And chocolate.

You won't starve for want of a three course meal. Anyway I think a room picnic of all the sinful items we deny ourselves is brilliant when I am on my own in a hotel. I don't drink, so it's tea/coffee or soft drinks, but if you do, a bottle of prosecco or your favourite drink is nice I'd say. Most wines have screw tops now, but bring a corkscrew if in doubt!

Just eat what you fancy on Christmas Day, then have what you can order from room service/get in a cafe for the other two days.

I hope you are alright and staying alone is something that you want to do, not have to do.

I am not in the UK, so things are different. Everywhere is closed on Christmas Eve from 2pm onwards. There are options for Christmas Day and 26th. I don't eat bread. Food at this place is pretty inedible these days, it used to be better.
There is no kettle.
I think grapes or other fruit and cheese is the way to go. Just remembered I could get some oysters :-)
Not my choice, but water damage means my house is uninhabitable at present.

How about a cool (insulated) bag? If you buy one and pop a bag of ice in (assuming shops where you are sell both) it will keep things cold for 2 days. So you can stock up on nice cold meats, cheese, salad, fruit etc for room picnics. Add nuts, dried fruit and some treats and you're sorted!