No eating

Ring the GP tomorrow and explain what she has been like in herself, say the last week or maybe since she git the antibiotics
If she’s not good to go with you first an appointment, ask for a home visit . This is quite within your right if someone is not fit enough to go .

is the access red and angry looking ? Like a red ring around it .? Does it look any better/worse since you took her to GP

If she’s still affected my the infection, as said infection can make you feel off, not wanting to eat.
The same conversation is a red flag sign if dementia. My MIL used to do exactly the same, she’d ask you the same questions and also numerous times in the day.
You could test her memory by simple questions
what day is it today?
how old she is?
what time is it ?
my MIL knew things from years and years ago but struggled with here & now

good luck tomorrow with gp and don’t let the receptionist put you off getting a home visit if your wife is too poorly in your view to make it in person

My mum had dementia and only stopped eating (and drinking) right at the end of her life, so it definitely sounds different to your wife's situation OP. As others have said, it's much more likely to be the antibiotics that are making her feel a bit ropey.

Alternatively, how are her teeth? Sore teeth or gums would be putting her off eating too.

There are various high calorie drinks you can buy, or would she like a hot chocolate with cream? Something like that would give her some calories anyway.

Definitely a call to the GP. Either the infection could be worse, which could also trigger the forgetful symptoms, or the antibiotic itself could be making her feel even more unwell.

Also if the abscess looks much worse, I’d be concerned about sepsis, which would require quicker intervention.

I find most antibiotics give me nausea and really kill my appetite, but contact her GP and they can change the type easily.

I think I'd call 111 and get her seen by an out of hours doctor.

Loss of appetite close to the end of life tends to be in those at the end of a long illness - the very late stages of cancer or dementia for example. It doesn’t sound as if that is what’s happening with your wife.

Definitely GP asap though. What has she said to you about how she feels? About why she doesn’t want to eat?

Okay, if this is your wife, how does the abscess look? Is it improving? Is the skin around it red and does it look there is active infection? Is she confused? Being tired and lethargic can be a result of active infection so if you are worried call 111 now and get advice. If not, call the GP first thing in the morning. Your wife definitely needs to be seen by a doctor.

I would also mention the forgetfulness and repetitiveness as it sounds like your wife may also have dementia. This, on its own, can lead to loss of appetite/forgetting to eat/not following hunger cues, but tell the doctor everything you're seeing and let him/her figure out what's going on.

It's possible that taking antibiotics is affecting her appetite, they can make you feel quite nauseous. Can you get the GP to do a home visit, or the district nurse?

How were the antibiotics prescribed - did someone see the abscess (gp?). Is she feeling unwell or just no appetite?

Can you contact her carers? Does she feel unwell in any other way?

Average life expectancy of a women in the UK is 83 so I think you can call her elderly, although she may not appreciate if you say that to her.

It doesn't sound like she needs A&E or OOH GP from what you've said, but a call to her own GP tomorrow might be in order.