Great job on maintaining control. That couldn't have been easy! And I'm so sorry that you keep getting stung, that really sucks.

I'm going to guess that you aren't actually being stung by bees, but by hornets (except maybe the one that went under your shirt). Bee's don't sting unless threatened because once they do, they die. Hornets, on the other hand, can be very agressive and will sting for apparently no reason. They are typicallly yellow and black and can definitely look like bees, particularly at first glance. I was just stung by a hornet while hiking a couple of weeks ago. It just landed on my arm and then stung me right through my jacket for no reason whatsoever! Stupid insect.

Are these stings happening in a similiar geographical area? It could be that you accidentally keep venturing too close to a nest and hornets will definitely defend.

Or like others have mentioned, you may just be having a run of bad luck.