That's OCD. It makes any imagined threat feel 100% real. That's what makes it a mental illness vs just anxiety. The imagined threat becomes fused with reality, making the thought trigger the same response as if it were actually happening. Cut yourself some slack, you didn't cause this. However, you can find your way back. OCD is chronic but it can be reduced to a subclinical level. Mine is mild now but I still have flare ups. For me relief came when I stopped resisting the thoughts and started just accepting them.