Good sleep comes to a relaxed and calm mind only. With so many thoughts running around in your mind, I understand that you are overthinking and overwhelmed by your overthinking, which causes you feel afraid and always alert, looking out for danger in your environment.
Next Steps
Please see a counselling psychologist for full evaluation. You can learn how to deal with such repetitive thoughts and also some natural relaxation techniques.
Health Tips
Practice anulom vilom and bhramri pranayma every day thrice before meals for 5 mins. Also you need to figure out which fears are realistic and which are imagined.