That if something good happened, something bad was bound to happen as a result. In my head I thought I never got to have, or keep, anything good. It would be taken from me somehow or something catastrophic would happen.

This is not the case. At all. I get to keep good stuff. The relationship between good and bad is not causal.

Yes, life changes things, the good may morph into something else, but it's still there, still recognizable. Bad doesn't erase good. We get to keep it. Bad is bad, good is good. They exist separate from each other.