One of the best ways to increase your self esteem is to do exactly what you are afraid of.
For example, my low self esteem was mainly connected with thinking I was uninteresting and unattractive to the opposite sex. So I often avoided speaking to them – that way I avoided all my worst fears being confirmed if I was rejected.
However, thinking like this becomes an unhelpful and vicious circle. If I had instead faced my fear and approached someone to talk to, one of two things would have happened:
a) I would not have been rejected and therefore show myself that I must be attractive/interesting enough
b) I would have been rejected and realised it’s not so bad after all – and built up confidence for putting myself out there.
(To be honest, the second option is usually so unlikely anyway)
So I would encourage you to try facing your fears head on and see what happens. Otherwise you will be stuck in a vicious circle of avoidance and never realising there’s no need to be afraid of anything.
You are strong, good enough to deal with anything.