Sinking, detachment is what you are experiencing. Sometimes we do that as a defense mechanism to heal emotionally. To experience harmful thoughts could be imaginations of retaliations of past hurts. If you can talk to a therapist. Definetly as for grounding techniques that you can use to keep you in the present and to focus on what is real around you. And perhaps talking with your doctor about meds might help as well. You are not alone. Keep posting here, we are a family who care for each other. I hope this helps. tc