Welcome to the club old man! I find that in my 60's I do not have the attention span I once had and easily distracted or trying to think way too much for no reason - (since I have all this experience and knowledge

??).
It sounds like you may have been thinking about the consequences at the end of the games - if that is the case, doubt creeps in and if you are not confident in your decision and playing with conviction, you're screwed most of the time. This is one of the 3 D's: Don't Do Dat!
Or...you are simply sandbagging as many do in leagues
I swear I will read your book soon!!!!!!
Dave