What is this weird feeling before my period?

[MarshmallowWorld]

1-2 days before and first day. I'd say it was a headache but there's no pain, maybe pressure. Head feels weird - need to close my eyes, want to go to sleep. Feels like my head isn't part of the normal world. Don't know if this makes sense!

Accompanied by very little patience and a sense I just need to get through the day quickly until I can rest/sleep

Pre menstrual tension, its well documented. PMT.

I suppose, I associate that more with mood but I guess it's all the symptoms. I wish I knew what the actual cause was though of the head stuff specifically - must be some kind of hormone drop