I am very hard on myself for my mistakes. Although I think this does have some positive effects it also has negative ones - in my case I find it harder putting in volume and feeling motivated if I have played a bad session or two.
Also, I think I lose a bit of confidence and focus at the tables as well.
I play my best when I am excited about poker and looking forward to playing but I think that is sapped to some degree by dwelling on my past errors, thereby preventing me from playing my best.

Any advice from people with a similar issue, past or present, could be helpful.