Could one help me how to express this properly?

Self-sufficiency is when you sufficient yourself. It is not imply that you should live alone and abscond from others.
Being a self-sufficient implies that you able to provide for oneself without the help of others.
This implies that you can afford to go to the movies or a walk alone and you are not bored you sufficient yourself for company.

If you are able to make an independent decision, not based on someone's opinion if you are responsible for yourself and you enough yourself to understand what should be done properly.
If a person is self-sufficient, he respects other people's opinions, but adheres to his opinion.
Self-sufficient person never grieve and he cannot be aggrieved - he has faith in himself and he has respects himself.
Self-sufficient people are not anxious about the past and not anxious about the future.

It's just essential quality of life. You must be able to do everything and to intend to work things out yourself and to depend on nobody.
You should remain alert to the possibility that if all men ever abandon you and even no one to help you, and you must begin to make decisions yourself. And will need to find the strength only in yourself to live.
Self-sufficiency is a very good quality of life. Self-sufficient person knows his own worth, and it is easier to achieve goals. After all self-sufficient people always what to do. If you always get bored when you are alone it does not speak in favor of you.
This is one of the main qualities that I emphasise in people. It includes many components. Here and independence of anyone's opinion was, and self-confidence and inner strength, and a clear view of the world, not cloudy prejudice and fear of misunderstanding.
The ability to not lose heart, never give up, do not take failure to heart and treat life as a game. No extra emotion, without despair. When nothing and no one need for harmony with yourself and the world and good humor, and the absence of someone close does not inspire feeling inferior. When wondering to yourself, when you know what you want and determine what really matters to you.
God is completely self-sufficient. After all, he created us in His own image and likeness, He gave us free will. A man may believe in Him, or may not believe in Him God determines our purpose but we determine our destiny.
God is the Supreme Being. There is nothing and nobody above Him. God is self-sufficient. He always has been and will be - He is timeless, He exists, who has life in Himself, He does not need air and food, He does not need water and space.