It seems to me that the French do not recognise in their psychological make-up much of a self-destructive streak, at least not themselves as lay psychologists; if this tendency exists it is not very important; nevertheless, the concept is not new as it is due to Freud, and it is known certainly to the French medical world.

“L’instinct de mort” corresponds to “the self destructive streak”; you can also say “la pulsion de mort” (encyclopédie libre). However, a term that is no less natural and a better literal translation is “la tendance à l’autodestruction” (see here).

The sentence could be rendered as follows;

• Il semble que je ne peux tout simplement pas sortir de ce cercle vicieux qui consiste à prendre en permanence et de façon consciente des mauvaises décisions. Ma tendance à l’autodestruction me pousse vers le pire des deux choix.

Mon côté obscur is also an option. 🙂