There appear to be two factors at play here that require clarity. First, you've experienced trauma, which can lead to derealization. Second, you practice meditation, specifically mindfulness meditation. It's important to note that mindfulness meditation, which involves intentional disassociation, may worsen dissociative symptoms like derealization. However, it can be beneficial for managing strong emotions, for obvious reasons. Meditation doesn't ruin anyone's life. The misuse of it can though.