Having massive MCAS flare—what helps acutely? Consider ER but afraid

Yesterday I took half a capsule of benfotiamine at 2pm. I couldn’t sleep but also had histamine foods at dinner so didn’t think much of it.

My MCAS has been in remission for two years now, I believe due to taking ozempic.

Today I woke up feeling massively depressed (not normal for me) and anxious. I thought probably due to poor sleep but it’s never been quite this bad.

I felt nauseated, but again, nothing too abnormal.

I have proceeded to have intense air hunger, whole body is clammy and cold, full BM evac all the way to water diarrhea repeatedly.

I realize this is a histamine response because I had a fraction of this back when my MCAS was raging.

What to do in an acute situation like this?

Feels like a panic attack though I’ve never actually had one.

Every time I go to the bathroom number two I feel like I’m about to die because of a sense of impending doom and then it improves post-BM

Should I take an antihistamine? I avoid them because they have given me brain fog and other issues in the past

I would prefer not to go to urgent care because of my history of being dismissed but I will if that’s the best option

Edit: the symptoms have passed. Most acute when going to the bathroom (sorry tmi). Once I was empty, body temp started regulating and blood pressure has raised. I waited fifteen minutes, notified my roommate and was ready to call an ambulance. Thanks for everyone’s tips. Wish this wasn’t something I’d experienced before but I have and remember a similar experience of it passing. Not the advice I’d necessarily give but try to avoid the ER if possible. I will be seeing my internist. Thanks again.