Dear Radha,
When I was in my teens and twenties I was extremely shy and afraid of social situations, and was often frightened in public. So I will share with you how I developed to become confident and secure. These approaches worked for me, so it will not work for everyone, but I think I have learned some basics which you can take and personalise for your own situation.
Being sensitive, emotional and soft hearted is beautiful, so don't think it's a bad thing, you just want to be able to function without feeling bad. Over the years I developed what I like to think of as a core of steel. I did this through repeated self care, and learning what my strengths were and seeing my combination of strengths as unique and valuable.
What are your strengths? What are you good at? It could be something personal like you are a loyal and reliable friend, or something professional like you're great at your job. It could be mental like you are great at solving logic puzzles or something physical like a sport. Write down all the good things about you and all the good things you do. Expand the list to be sentences for each attribute. Use this to build a strong picture of yourself as a good and strong person. Keep it by your bedside, in your bag, look at it every day.
Care for yourself. I used to have bubble baths and sometimes take a long time over personal grooming, not to look good for anyone else but in an almost ritualistic way with the conscious thought that I was caring for myself and I loved myself.
Keep a mind on your future by always being mindful of what it is about yourself you can improve. I always try to acknowledge my weaknesses and mistakes, I want to learn from my mistakes and become a better person. In this way I hope to avoid arrogance.
Weakness and tiredness in your mind may be because you are expending so much energy stressing and worrying. You did not describe an example of what situation you cannot face so this is hard to form a good reply. Is it people you don't want to face or something non human?
It sounds as if you are almost paralysed with fear. Feel the fear, acknowledge it, analyse the root cause of it and you're on your way to a cure.
Be strong!
Good luck!