Dealing with Unexplained Allergic Reactions

I have a weird thing going on and was wondering if anybody could point me in a direction to continue research or relate to it, since I've never really met anybody else with this issue. It started in 2018 when I had about 4 bug bites on my back in a close area, bitten within hours of each other. I went into anaphylactic shock, and it was terrifying. I started seeing an allergy doctor (cant remember the official term right now) but we couldnt really come to any conclusion. I haven't gone into anaphylactic shock a second time, but I have had pretty bad allergic reactions to all sorts of things. Periods that are very painful, fevers, a single bug bite close to a vein or artery, other cases of multiple bug bites at once, and one time when I had an allergic reaction and I still dont know why. My doctor came to the conclusion that I'm sort of allergic to physical stress- if a situation has my body working hard it will overreact. can't remember if that's immune or auto-immune right now. She couldnt give me a name of a condition or anything like that though. I take an antihistamine every morning as a preventative measure and it has lowered my rate of reactions a lot, but they still happen occasionally. They will knock out 2 to 3 days of my energy when they do occur.