Sometimes it makes no sense at all

I had a good night out on Friday and I should be feeling chilled and relaxed, but I am totally wound up and very jumpy.
Its like I have my own personal demon just throwing me often balance when I think I have got it all together.
Whats it like not to jump at your own shadow?  I wish I knew and I wish someone else could actually know what it is I am talking about, but it will make no sense to them.  I do feel that as the days go by I am losing it more and more day by day.
Whats lurking in the shadows? I don’t know, but I feel like there is something chasing me…