I tend to agree that it's related to the stress of your new realization. If your mood is on the depressed side, you could be suffering some nonrestorative sleep issues. When you are depressed, your sleep patterns are off and you tend to feel fatigue.
Take care of yourself in general. Eat well, maybe take a vitamin and try to get some exercise every day. Also, work through the shock of learning TTATT. I'm willing to bet that this problem will subside when you get over the emotional shock and your personal life is back into some semblance of a (new) routine. If it lasts longer than a month or two, consider going to the doctor and getting screened for depression.
Until then, the advice given is good. Avoid computer screens before bed, get exercise, shut the bedroom door to avoid interruptions, keep the room very dark and run a fan for white noise. Benadryl is an effective medication if you really need help sleeping.
I really believe this is about your psychological and emotional needs right now during your transition. The body responds to the mind. And, it's okay to get a little extra shut eye right now. We process things during sleep. You're just mentally overloaded right now.