Novel events are indeed more stimulating to our dopamine receptors.
Our brains are also wired with a negativity bias. A substantial one.
It takes five positive events to override the impact of one negative.
Our Brain's Negative Bias
Why our brains are more highly attuned to negative news.
With self-awareness, commitment, and lots of practice executing cognitive overrides, we can break out of the compulsion to focus on the negative/devalue the positive.
Habitual catastrophizing is a habit worth breaking.