Since I'm coming onto this as both a HypoThyroid "and" Low T person it might do you some good to have your FT3/FT4/RT3 checked (Thyroid). Most doctors will NOT check these on a standard blood test/draw. All they checked was your TSH which is NOT a good representation of how/what your Thyroid levels should be "optimally". Have you ever had a 24 hour salvia test (Hypoadrenia)? Your heart palpitations/hot flashes are the exact symptom one has when they have low cortisol levels late at night/early morning. This is the time of the day/night our circadian rhythm slowly switches from lowering melatonin to raising cortisol levels. If you have Hypoadrenia (low cortisol) and the body can't produce the needed cortisol it reaches for the 2nd best hormone which is adrenaline. Adrenaline will give you heart palpitations and hot flashes (this is exactly what it did to me). Do you have fatigue in the early morning hours?