Suggest Treatment For Hives

A couple weeks ago i went to a huge party and i smoked weed twice and drank about 6 or 7 beers. Later that night i got home and began to relax and my legs started itching. I thought they were mosquito bites because i was outside the whole night because of that party, but when i finally got fed up with the itching i got up and took my jeans off and i had a bunch of hives all over. Shortly after i realized i was getting the hives all over my triceps, foreamrs,back and neck as well. I started to get scared and my heart was beating fast the whole time and it was hard for me to breathe. What happend to me?