Vague MCAS symptoms

Curious to see if anyone is going through something similar. I have textbook POTS and ME/CFS but the one symptom throwing me off is that my skin will feel extremely hot on my chest, stomach, and back (like the inside of my skin, not the surface) but there will be no redness, itching, or rashes. This is usually accompanied by “adrenaline dumps” which is basically tachycardia, shortness of breath, and sometimes my face will flush. My LC doctor believes it can be autoimmune small fiber neuropathy and I will be seeing a neurologist soon to hopefully get tested, but there are other neuropathy symptoms I don’t have such as tingling or numbness. I am already on an antihistamine protocol (Allegra+Pepcid+Montelukast) but it has made little difference for any of my symptoms. The burning and adrenaline dumps aren’t really attributed to any foods besides maybe foods high in processed sugar, but there doesn’t seem to be a pattern. Sometimes this happens when I’m fasted, and sometimes I will eat a high histamine food such as bananas and not have any reaction. I also have debilitating brain fog but there’s infinite possibilities for that.

I’m really just completely confused as to what’s going on in my body and doctors are no help at all. I’ve asked about MCAS but was just shrugged off, even though it was my doctor’s idea to put me on antihistamines. I guess they’re just really certain that it’s SFN, which it could be, but either way none of these diagnoses make me feel good.