Been stings!

So, last month a friend of mine and I went in on a honey bee hive and we put them on a farm about 40 min from where we live. We went to check on them today and I got stung like 9 times! 7 times on my scalp. They kept getting in my hair and then getting stuck and stinging me. I have checked them before without my gear on and not gotten stung. I knew it was a matter of time, but boy does it hurt! My head feels like it's on fire. Does anyone know how much benadryl I can take? The other areas I got stung are a bit swollen.