Suggest Treatment For Itching And Redness After Deer Fly Bite

I was bit by what I believe was a deerfly. I had about 5 bites a few months ago and they were so itchy, painful and red for 3 weeks! It took longer for the scars to go away. I just got bit again on my ankle two days ago. Yesterday I had a huge raised "white/yellow" area where the bite was, about the size of 2 quarters. Now, this morning, the whole side of my ankle is swollen and the itch and pain is unbearable! I have been using benadryl cream, but it doesn't do much. I am traveling in one week overseas and will be on 4 flights, one is 15 hours! Is there a shot or anything that would help speed the healing? Would you say I'm highly allergic to these bites? thank you