Don't underestimate the caffeine!
I was drinking a lot of strong coffee daily years ago and decided to stop (relating to mc issues) and foolishly stopped cold turkey not having properly assessed/registered how much I was drinking (culture of place I was working at the time meant constant "top ups" so hard to know how many cups I was having at first)
I ended up feeling extremely unwell, it was around this time of year and i honestly thought it was a bad flu I felt so rotten! Luckily dr twigged quickly what was wrong and advised me to reduce caffeine more gradually, to wean myself off it.
The combination of caffeine, sugar, stress could definitely leave you feeling like this.
I'm sure many other posters will agree that the stress of a situation like worrying your child is seriously ill can end up having a delayed effect - because we "power through" to support them and others that are worried.
Sometimes it's the "relief" hits you hard and the drop in adrenaline.
Make an appointment - but you could well find your practice nurse can help with this and you don't necessarily need a dr appointment.
My gp surgery you can self refer to a cpn (community psychiatric nurse) for things like this too.
You could even find some good advice online.
The common sense but easily forgotten things like...
Make sure you're sleeping as well and as much as you need
Take time out for yourself to do something you enjoy (hard at this time of year I know but it doesn't have to be something out the house or that takes long. I enjoy singing I've done it from a young age and find it soothing to just hum sometimes or sing a full song - it also helps regulate breathing to a calm level)
Eat and drink well - most of us don't drink nearly enough and I don't mean coke/coffee preferably water but if not weak squash, milk at times (great for nutrition and a "calming" drink) or fresh juice (not too much as so high in sugar), try to get your 5 a day
Stretching exercises - to relax tense muscles. I have particular trouble with my neck when I'm tense leading to headaches, I do tend to reach for the painkillers but I am trying to remember to do neck exercises physio showed me
I hope something in all that helps.
I suffer from anxiety awfully and could do with taking more of my own advice! I try as much as I can don't always manage it so certainly no judgment here and it's a stressful time of year.
Maybe shopping malls should have yoga rooms?