Once you have established some time to get to know yourself and realise what it is you must do that will make you happier or reach your goals, set yourself about building a bridge to beat the problem.
The process of going from no self confidence to being fully aware and self confident can be a long and emotional one. i recommend you speak to qualified professionals about this issue too. As much as I enjoy being able to give information, I am not a mental health specialist. I can only offer you my own story from being a timid teenager with not much view of myself, to the present day where the sky is my limit. This process can be done but it has to be gradual, laying each brick of the bridge one by one- yes it might collapse but then you start over. You have to keep going.
Like any behaviour change this part is the hardest in the cycle, deciding to make a change is ‘easy’ compared to working towards that change. Every day is unknown territory and you often feel like you make no progress or that you’ve stagnated.
Set yourself the routine to improve- like in part 1: Spend time with yourself and ON yourself. Nothing amazing is built in a day and confidence is the tallest tower, the widest river and the biggest opponent.