Thanatos...Observations inspired by Freud's "Beyond the Pleasure Principle"

There is a strange, but unmistakable phenomenon that I have observed while I play poker. The better I am playing, whether by skill or luck, the better (usually) I continue to play. The worse I am playing (whether to playing unskillfully or due to bad luck), the worse I continue to play. What I mean is that when things are going well, I make good decisions. When things are going badly, I make poorer decisions.
Why is this? I mean, if things are going poorly, making better decisions will lead to better outcomes as well. At the very least, poorer decisions will not lead to better outcomes. I know this, yet I would not be writing this unless there was something to it. That is, at times although I am aware of this tendency consciously, I nevertheless, often continue to make poorer decisions...despite knowing better.
There is a tendency we have to preserve what is good. Thus, if I equate me = good player I wish to persevere. On the contrary, if I feel I am a bad player, I wish to destroy this being...insofar as I equate - me = bad player.
I write this not just so that I may attempt to fix this flaw for the sake of better poker, but because I believe that this can be extended generally to what we do in our daily lives.
Thus, those aspects of ourselves that we cherish we continue to cultivate. Seeing them flourish, leads to further cultivation. Other facets of our lives and selves, though they would benefit by the same cultivation, we often do not put the extra care and concern required that they may thrive. Rather, we do the opposite and seek destruction. Such self destructive tendencies of course seem to serve no purpose, and yet they must be acknowledged.
There may be a tendency even to destroy what is good. That is the unity which we take to be our self...when we realize that this unity (even its best aspects) too must eventually perish, we would no longer put such cultivation into these aspects either. Realizing this, might we not, then, even sabotage ourselves?
Thus, what to do when you have achieved even your highest aspirations? What then?
Striving is often more enjoyable than obtaining. Once a desire is fulfilled it is realized to be empty. Self Destruction, or Transedence of some form (or both) may then be sought.