I'm sorry you are having such a difficult time. Anxiety, fear & paranoia are things I struggle with a bit as well although not to the extent it sounds like you do. Unfortunately, I don't have any secret remedies to share with you. The technique I employ to deal with my own concerns is one that is referred to as "compassionate abiding". It's a Buddhist technique thoroughly delved into in the writings of the American Buddhist nun Pema Chodron. However, here's a link to a mental-health-oriented description of the practice:

Relieve Distress By Allowing It: Compassionate Abiding 101 | Mindset: Perspective Is Everything

Given what you wrote, though, my inclination would be to say this technique may not be adequate to address your concerns; and I would think seeking the help of a skilled mental health therapist might be the way to go. My best wishes to you...