Harvester Ant Bite 2 Days Ago. Area Of Swelling Gets

Harvester ant bite 2 days ago. Area of swelling gets bigger now is maybe 10" x 10" on thigh. Red and hot. Not too itchy. Have taken some anti hystimine. (Zantac) Will take Benadryl tonight - can't take it and work or drive. No other symptoms. Wondering if I should go get a shot at a clinic. These ants always make me swell up live this. Wasps too. Bees not quite as bad.