Don't rush and give up. Some years ago i was bitten on the inside of my wrist and for some reason did not notice it. Some 2 hours later while sitting down indoors, i realised that i was itchy all over and that my face was gradually going numb. Went to my local Gp and communicated via written note what had happened. Luckily not anaphalaxis and was presecribed some steroid tablets which restored things to normal.
I was really cautious after this but soon picked up a couple of stings and had no reaction. Now try to rapidly apply antihistimine cream to the site of stings which seems to work even when i stupidly didn't close completely one of the zips on my veil do that 5 or 6 bees rapidly found their way inside. Not to recommended!