One of the worst things you can do is to permit a continuous trickle of worry across the mind, because like water it will ultimately dig a huge trench. Then every thought you think will be drained into this channel of fear and worry and come up tinctured with anxiety. You will be a person full of fear and worry.
The way to obliterate this is to start another stream. Let a stream of faith run across the mind and go deeper and deeper as you absorb faith thoughts into your consciousness - and after a while, it will undercut the channel of fear and worry which will then fall into the Chanel of faith, and a great river of faith will surge through your mind so that every thought will come up bright and resplendent, optimistic and hopeful, and life will be good, very good. Cultivate a channel of faith to give you deep security which you need.