Trouble is when you are unwell, the body decides that it needs to sleep in order to heal itself.
This is all well and good except that the body does not care whether it is 10am or 10pm...sleep it wants, sleep it demands and sleep it will have no matter how much you fight it.
Once you are feeling better, your sleep pattern has pretty much gone flying out the window and you end up having to retrain your brain as to when it is an appropriate time to sleep.....as in not mid morning, when bored whilst attending that meeting or sat in the car waiting for the other half to finish the shopping
Just as with my braincell that I put in charge of listening for the alarm at 3am still refuses to be retrained over 15 years after I stopped working......some bodies take longer to get the message than others in relation to when sleep is appropriate and when it isn't...and some, well they just never get the message and you are plagued with 3am wake up calls for the rest of time
Sadly the human body is not like a computer that we can reboot when it goes awry....we have to retrain it, which can take a long time....or we can force it by using Valerian root or melatonin to trick that one stubborn braincell into co-operating...or we can take up reading extremely boring books at night, but that can be hazardous if the book flops onto your face and you wake with a black eye or two
Getting out of a healing sleep routine of being asleep at the wrong time of the day or for longer than you would normally sleep is extremely hard, sometimes needing medical intervention to make sure that the sleep disturbance is just down to being previously unwell and not due to something more serious. The use of "assistants" like Valerian should only be used for 2 weeks, if after that length of time you still have sleep disturbances, then a visit to the doctor might be a good plan, just to make sure there is no other reason why its happening.