We found exactly the same thing this year. My wife often gets a bit bitten, whereas I never get any, but this year they got all 3 of us. We did the same thing as you, visited a couple of pharmacies and got varying degrees of repellent and relief cream, but the repellent just didn't seem to work.
The cream was good for calming the bites down afterwards, but 3 days after we returned mine suddenly got really angry and I ended up having to get a course of antibiotics! Only today have they just about gone, a week after we got home!
Of course, it won't stop us visiting in the future (summer 2019 is currently being planned), but your message makes me glad that it wasn't just us - although I'm obviously sorry that you had to suffer as well!