By working to believe in urself little by little each day. If u view urself in a negative light then it will come across in attitude and you will never feel free enough to live and let go.
There is no easy fix sorry. I have this problem off and I found things that help but it comes in waves. (high and low)
Working out is a good way.
Making a list of actionable things. (tasks that can be done i.e. clean stove and not clean house.)
Looking in the mirror and forcing yourself to say good things about yourself .
other then that I dont know of any cures sorry.
, Depending on how deep the issue is with you, self help books may help. If u go to your library or look on amazon paul mckenna and deepak chopra have written some great books on this and similar subjects, give them a try at least. The mckenna one has a cd with it which is really helpful at reinforcing positive thinking and affirmations and includes some guided meditations.
Also zen buddism has some very self affirming points and is also worth looking at, just a matter of finding what works best for you, dont give up though, often we have to try several things before we discover one that suits our needs best.
CBT can also be helpful specially if negative thinking/self talk is part of your esteem problem as it helps re-train your brain to counteract these destructive influences and
replace them instead with rational and positive thoughts, it also encourages you to set small achievable goals as you go along to track your progress, allowing for self reward, so you can feel proud of yourself.
Some of this stuff worked for me a while back in rehab when i did a confidence building course, so now if i feel low in this area i go back to what i learnt and it usually sorts me out pretty quickly!
good luck, hope u find something that helps you.