The only way to turn them on again is to socialize with other people despite the anxiety. You will see that as you push on, the brain will activate those circuits again, and the anxiety will soon fade away. You could also be afraid that the anxiety will not go away but this is actually the anxious mind finding more things to be anxious about. Anxiety can be crippling and burdensome because you require a complete guarantee before you take your first step. So go and take the first step before you begin to question on whether it will work or not.