Knowing that there are things you can do today which can change the way you feel is a great confidence booster. For example, start to make a note of all the little things that go well every day. Often, we tend to disregard them and focus just on the bad stuff. And then we start to fantasise about all the terrible things that might happen. Catastrophes in the making.
Take active note of even the smallest positive thing. If someone talks to you at the bus stop, give yourself a point. When you find yourself having an unhelpful thought, tell it to go away, and reward yourself for taking that action.
Unkind and critical self-talk is destructive and achieves nothing. Hypnosis can help you get out of the habit.