We have many "Erroneous Zones" in our personality some are known and many are unknown. What's is unknown can never be acted upon. One of them is the 'Inhibition' to express our feelings. Unexpressed feelings build pressure in us waiting to explode one day.
What is the genesis of this inhibition? When we were a small child our parents controlled us, later our teachers, spouse, boss and so on. When we try to express something we encountered 'put downs' from parents to start with. A frequent 'put downs' created a loss of 'Self-esteem' which ultimately resulted in our 'Inhibitive behaviour'.
When we don't know the root cause we can't correct it. The first step is to know we have this problem of expression. I remember the story of the elephant tied to a plant never attempts to move as it is conditioned that way from childhood.
The second step is to revise our self-esteem by auto suggestion that we are a worthy human being. If you don't respect yourself, no one will! You are a wonderful creation with your own virtues.
The third step is 'Do the thing that you are afraid of' ie speak your heart to your spouse at least once a day. In your office, start expressing your views tactfully as people are waiting to see you the old way. If there are 'put downs' handle them firmly. Then you will find a new Freedom dawning on you.
May Lord Bless you with lots of expressions.
With whole of heart