Most of the things you listed in the first paragraph are things that don't sound too urgent so perhaps you could put that off for a while?
If your ceiling is in bad shape that could be a problem that needs to be addressed sooner rather than later.
How badly do you need a new car? Is it about to fail while you're driving or become unreliable when you need to get somewhere?
Is there another form of transportation you can use to do the necessary, and which does not involve the purchase of a new vehicle imminently?
Birthday presents.
Not very specific, but if you must give them perhaps you can look for something creative and certainly less expensive.
Xmas, sorry this is very personal but I think I would think twice about posting Xmas gifts if I was feeling as overwhelmed about finances as you are.
Dog needs to see a specialist, is this the veterinarians advice?
Do not let your dog be in pain or discomfort.
Only you know what has been recommended, but getting your dog seen too properly is more important than posting Xmas presents overseas to people who I'm sure who would understand your situation, if you explain to them.
You have medical problems as well, and yes they will likely involve appointments.
Then you must go to them, even if you have to take another form of transportation, if you are unwell you cannot work.
Try some breathing exercises for relaxation, they do help when you feel overwhelmed.
It's not a nice place to be.
Write down what your priorities are, I would say your ceiling if it's in really rough shape, your health and that of your dog.
All the rest you might just be able to manage and or put off for a while.