Can’t you remember when you got a new car, and all of a sudden, you see the same car everywhere. We see what we focus OR don’t focus on. The same happens with our thoughts/feelings. Positive thoughts/feelings attract more positive thoughts/feelings, which in turn confirm to you a life that is more positive, therefore make you think more positive thoughts and so on… Negative thoughts/feelings  attract more negative thoughts/feelings,which in turn confirm a life with more negativity that in turn fosters more negative thoughts and so on…I am not suggesting suppress your sadness and pretend to be positive. I’d rather want you to see that you are sad and feel it, while at the same time searching  for something (image, feeling, memory …) that makes you a feel better and so on until you feel at least neutral. Try to make yourself aware by watching out for your sloppy thoughts and keep focusing on thinking/feeling what makes you feel better.