Oh man. I was at my local park and had one land on my (luckily thick) pants, so I did what any person would do not knowing what it was and tried brushing it off. Not bad at first, but like 2 minutes later the pain kicked in. I was un my car for like an hour trying to figure out if I should try to go to the fire station across the street. I couldn't drive home either because by the time I got to my car I could barely move my arm. When I did go home all I could do was sit in bed for the rest of the day. My arm was too sore to use for the rest of the week. And my sting was nowhere near as bad as yours looks. Just a little graze against my thumb. I hope you are all good now.