I would rather miss a holiday than (a) travel without insurance or (b) continue to see an incompetent and inconsiderate doctor.
You're a patient and you have rights. That includes the right to an adequate standard of care (ie a doctor who knows the basics of their duty to use the correct tests for a serious illness like diabetes). It also includes the right for the doctor to understand that your holiday is now at risk (unless you see a different doctor/medical practice completely).
I would also recommend that you get your insurance sorted earlier next time. Leaving it until the last minute has caused you unnecessary stress IMO.
You already had some of the risk factors for T2 diabetes before this, and your doctor had a duty to regularly screen you for it. Hypertension is often diagnosed before T2 diabetes develops. Both conditions need careful long term management and they are interrelated. IMO you will also need to monitor your cholesterol levels from now on.
If this doctor messed up diabetes testing this much, can you really trust her with your life? We have to be able to trust our doctors to be competent.
I hope you exercise your right to choose a better doctor. If not, you can find good up to date information here about the correct testing and management of diabetes.