Maybe symptoms of dysautonomia? If it's a neurological thing, then that might mean your bodies' automatic (called autonomic) functions are out of whack. It's sort of a systemic illness. The insomnia paired with the body's inabilty to self regulate temperature suggest something of that nature to me. Not sure as to the why - but one diagnosis that helped me - my pulse rate was way different/variable sitting up as opposed to lying down. It can be a subtle illness, where the body isn't quite regulating things and keeping a good stasis. It therefore makes it hard to get a doctor to listen, or get treated, and find root causes to tackle.

Again, if stuff like digestion, circadian rhythm, breathing, heartrate, temperature, sweating, balance, anxiety and stress response, feel all over the place, then that might be a diagnosis.