Pre Monday Syndrome (PMS)

Yes, PMS in my dictionary also means Pre Monday Syndrome.

I had this feeling 3 years back and now I am feeling it 2 times more than before. I have been in this new job for almost 4 months now, but I still have this crappy feeling. I wanted to confide or ask someone why am I having this feeling - I tend to worry and think about my work on Sundays. I work on Sundays in between the day and before I spend sometime out with my darling. 

I wonder if it is because I am slow in doing my work or is it just too much on my plate or is it just that I still haven't fully adapted to the super fast moving industry?

I wonder, I ponder and I hope there is an answer for me soon..... It really makes me uncomfortable.

I have read an article before stating that a person should be enjoying what he or she is doing ; approximate 50% is what the person knows what to do; 50% is the job provides new learnings and experiences. If it is 70% of unhappiness with the job, meaning the person is not the right fit and should look for other opportunities. 

And I wonder....