Adjust The Sails
The question is not so much whether your thinking is 'negative' or 'positive.'
The more important question first is:
Is your thinking rooted in reality?
The school of positive thinking monotonously teaches that 'nothing is impossible,' but our world is deeper, more wonderful, and more complex than a place in which simply nothing is impossible.
The doers of the impossible did it by honoring and therefore dealing with and working with - REALITY.
Have a real day.
And don't be afraid to adjust the sails.