Oh, you poor dear! What a huge change! And a big loss too. I hope you're being gentle with yourself.
The flushes I mentioned don't last more than an hour or so. And then there's the hormonal flushes…those are about as much fun as discovering a whisker on my 50-year-old cheek.

(I use a progesterone cream that has helped soften the ride somewhat.) And yes, my face and ears get hot to touch. If I want to impress my friends with a parlor trick, I could just pop a few niacin and wait for the show to begin.
That's got to be worrisome if you've been flushed since July 4th. Because your tests have all been negative so far, I would totally treat it like TMS which means using strategies to get your mind off of stressing over it. Yeah, I know…easier said than done! For me, one of my hardest symptoms has been a knotted achilles that gets very painful and makes it difficult to walk.
It got so that I'd wake up on the morning and would check to see how large the knot was. I put a stop to that. And when it feels tight, I do not allow myself to feel around to see how bad it looks. (It has gotten walnut size.) NO MORE!!! Instead, I ask myself…what am I afraid of? Why am I afraid to step out? Remember TMS is all about distracting your from the emotional issues.
Is your flushing telling you that you're really "burning up inside" about something? (Geesh, with all you've been through, I would think so!)
One thing I try to do is when I have a symptom that's bothering me, I'll sit quietly and ask my body what's going on. Learning to still the gerbils that frolic about in my head is no small thing but I am getting better at tapping into that inner wisdom that we all have. It's only found in stillness.
Hope that helps a little more.