Hi there ~
can be related to poor sleeping habits during the night. It may be a good idea to see a sleep specialist. If you are snoring
or are waking up in the middle of the night and not being able to go back to bed or a having troubles initiating sleep or waking up too early in the morning it may be an issue that needs to be addressed. If everything about your night time routine is right, you may have a primary sleep disturbance in the daytime which is affecting how you are performing during the day. I think that sleep attacks during the daytime are curable with a bit of medication. However you need to see a qualified psychiatrist
to get the medication going. I hope you are having no other medical problems.
I hope this helps. Take care and see you soon !