For sure see your GP and also the optician, maybe dentist too if it's been a while, opticians can often pick up things. It may take time to get an appointment, I'd suggest you get a blood pressure meter yourself, and start doing readings as soon as you can, our docs don't lend out meters any more. Tiwce a day, and sit for 5 mins before you do it, and take at least 3 readings,maybe more if they fluctuate, not within half an hour of eating and drinking or exercise. You'll be able to take the readings along and it will give her some useful info.
I'd also do a bit of a diary, of what happened that day, and how you felt, food and drink you had etc, if it's not as bad some days or much worse others, this might be helpful. You need to rule out things that need medical help first, you can check simple things like bydration yourself. Think back to when it started, too.
Headaches are miserable and waking up with one is a rotten start to anyone's day. Hope you find some answers soon