You should not avoid experiences because they freak you out but engage in everyday life as fully as you can and reflect on what has been difficult afterwards. Think of what you have done well, or handled well and tell yourself you are a competent person. Those incidents that you feel you have handled poorly, discuss with another person, someone who is calm and competent themselves. Often those who readily offer advice just like to hear their own opinions are may not be the best guide to how to act.
Having experiences, reflecting on them, re-working what has gone well and trying to act even more competently the next time will increase your confidence. No-one can avoid upset and misery occasionally but hiding away is not the answer. Face your fears, and do a little part of what seems too difficult, and a little more each time. That way, you will succeed and feel proud of yourself.