I had a dream that I was in my backyard with my friend Lucy around the pool. All of a sudden I couldn't stand, but I could crawl. Then (my head picked this number in my dream) 21 angry wasps flew in and started to sting me. Only me. Then I got a view of my back after they all flew away and (my head picked this number too) I had 21 big bumps on my back. I also had two big bumps on my left arm, and then on my right arm. Same spots. Then in the blink of an eye, I was in my father's blue 2002 Chevy Silverado. I was slouching in the truck, while my father was driving. We were going fast (my father speeds a lot) but I don't know how fast. My window is rolled all the way down, and one angry wasp is flying beside the truck. Occasionally it would fly in the truck to try and sting ME, only me, but I would swat it back outside. I swatted it away 3 times and then I woke up. What does it mean?
I can relate a personal meaning for wasps, and you can see if it rings true for you.
My ex had a phobia about bees and wasps. And every time he experienced some problem at work, or a personal situation that had to be dealt with, he would inevitably have dreams of bees or wasps. For him they meant stress and being metaphorically "stung" by something going on in waking life. Ask youself whether there is some annoying issue in waking life that has been buzzing around lately.
The number is probably meaningful for you. But because numbers in dreams are usually quite unique to the dreamer, I can't tell you with any certainty what that is. It can be a length of time, an age, part of an address or phone number, or any number of other things. Are you 21, or turning 21 soon? Did something significant happen 21 days prior to the dream, or is something significant supposed to happen 21 days after the dream? Has the number 21 popped up in any other way recently, that your dreaming mind would have grabbed onto that? Twenty one is the age of consent in many places - perhaps it represents autonomy of some sort? Discovering what the 21 represents for you might offer some clues as to what you're afraid of being stung by.