It has been FOREVER since I've gotten stung by a wasp and MANNNNN those suckers hurt!!!
I know, when you get hurt, stung, burnt, injured in any way, your brain is not always in focus mode and I'll tell you what, my brain was in "OUCH what did I do to you?" mode. This is why I highly recommend either a published natural and/or herbal handbook or small notebook in which you've jotted remedies. So that you can look up what you did: "Bee Sting" and flip to the page, so that when your brain is numb, you still know what to do.
Luckily I had compartmentalized this remedy in my brain and jumped into action. You guys, this is safe for the tiniest sprouts, so keep this one handy!
I immediately washed it with a bit of natural soap and water, dabbing gently. I scraped a credit card across it (not squeezing, you can release more toxin that way) in case the stinger was still in there. Sometimes, though the swelling is immediate and it holds it in. You may have to try again later. The longer it stays in there, the more swollen and painful it gets.
I used a little arnica gel for pain and swelling while I was making my preparation. I took a tissue, soaked it in apple cider vinegar (this was a wasp and their venom is alkaline, so apple cider vinegar or lemon juice will neutralize it. If it was a bee, who have acidic venom, use baking soda and water into a glue like paste).
I ran out to the yard, and luckily we have the kind of yard that has PLENTY of weed growing in it. (No, it's not laziness...why would I kill nature's medicine? Some I have transplanted into healing gardens, but something like plantain grows so prevalently and is good for so many things, I certainly am not going to hinder it's growth. I grabbed 3 leaves. Plantain is one that I have shown my kids many times exactly what it looks like. "I know, mom. If we ever get bit or stung, this is the one to grab."
In my mortar and pestle (but you can just use a rock and a hard surface) I crushed the leaves, drizzled a little more apple cider vinegar, and mushed it into a leafy pulp. To this I sprinkled a little charcoal powder to help pull toxin from the skin. 
Now, I took the whole homemade poultice, applied it to the sting, and wrapped it in plastic wrap (for lack of anything else handy at the time). Now, I could apply ice.
Buy the time I got to my computer to start typing this out, the pain was nearly gone. I still have it on though, because I don't know if I got the stinger out. It can be left on and reapplied again and again as needed.
Of course, I am not a medical doctor, or emergency room attendant and I am an educated, but still LAY herbalist. I do not have anaphylaxis to stings, but there are PLENTY of people that do, so silly, be smart, seek help.
Now, that was only the OUTSIDE, I still had to work with my body as a whole. Now that the emergency acute measure was taken care of, I asked my body what it wanted to eat, drink. Because sometimes it DOESN'T, so pay attention.
First thing's first, cool water with a little lemon, for calming and to help neutralize any acidity the stressful situation caused (any time the body has to react or fight anything can cause an adrenaline rush. Plus, it had been a LONG time since I"d been stung and I really didn't know how my body would react, while I watched for signs of anaphylaxis).
Lemon can also work as a great detox.
Next, I made a potato soup made with coconut milk, sage and pepper.
Here's the recipe:
And here's the how to video:
https://www.youtube.com/watch?v=0jaBQaXcC50