1. No fear of death or the after life
No belief in the after life. Also, no fear of death. Like Lucretius said — the feeling of death is the same sensation of never being born, or the feeling you experienced before your birth.
2. Physiological anxiety
Just monitor yourself. Just note the physical and hormonal changes which happen to you when you feel anxiety. What triggers it? Your email inbox? Your bank account balance? Nip it at the bud.
Detox from both uppers and downers for a few days or week. No weed, alcohol. Cut caffeine and other stimulants for a day. Spend a whole day just drinking water, walking, and sleeping. Eat a lot of meat and recover.