Overthinking Anxiety And Fear.. My Husband Had Death Fear Related

Overthinking Anxiety and fear.. My husband had death fear related to his BP medicine. Which he didn't tell anyone for a month and he got anxiety. Now, he is fine anxiety. But Overthinking is there due to fight flight mode and what he had gone through. This Overthinking is very much controlled with grounding like 5 4 3 2 1 , 4 to 6 breathing , washing face, reposture. Only few thoughts becomes Overthinking. He gets over emotional sometimes. He himself got out of this on his own without any therapist. We want to make sure what we are doing is right or not. When will his Overthinking stops and ways to stop.. Why this leads to fear and he get imaginary thoughts of various things in daily.. what we can do further to lead a normal life.. He has resumed his work and goes to temple, plays badminton which is also helpful.