Frustrations

You might find the information here helpful:

NHS - Home blood pressure monitoring

If buying your own (rather than one supplied by the NHS), it advises “To make sure your monitor is accurate, choose one that has been listed as validated for accuracy by the British and Irish Hypertension Society (BIHS)”.

In turn, as well as providing a list of validated monitors (click on the down arrow on the linked page to show the list), the BIHS advises that “The BHF Gift Shop only sells monitors approved by BIHS”:

British Heart Foundation gift shop - blood pressure monitors

My nurse and I have found that looking at pictures of dogs between the first and second blood pressure check is the trick to get it below the concern threshold. I imagine an actual dog would be even better, but regardless, it may be worth trying to find a specific calming thing.

Alternatively I agree with Stuart that home blood pressure kits are generally easy to use and allow for less stressful blood pressure recordings. 

Don't those fitbit type of watches measure all that stuff? I think you can even send your readings to your doctor?

Clever! I’ll have to remember that for situations where I feel stressed. Sadly, I don’t think it would work with border officials at airports.

Indeed.  To save time and hassle travelling I would consider taking my own readings and reporting them per monthly visit.

The Omron blood pressure monitors are c. £25 then you can test as much as you want at home when you are relaxed.

I don't know if that is within reach or if someone could help, as a present or something.

Okay so this will sound silly, but I have figured out a fix for me when it comes to dealing with needles and blood pressure tests.

I inform the nurse that I’m Autistic and I can stay relatively calm if we talk about something I’m interested in. So I’ll usually launch into a discussion about music history or some nonsense. I stay calm and the nurse might learn something useless about music! Win/win!