I am not a medical professional but it seems to me that it’s lots of stress you are under.
Have you ever tried staying up all night and then starting the new day? If the following you feel tired at 7pm, so be it, enjoy your sleep. The next day you’ll stay up later.
Also, I hear there are lots of differences among the amount of sleep different people are used to. You should consider how many hours of sleep usually make you feel you rested well, and then compute according to that.