In short: stop believing your own opinions about yourself. These opinions are not really yours, they are the mind's concepts - a self image, which has nothing to do with who you are. You are nothing to do with concepts or opinions, you are the awareness behind them.
The opinions of others that concern you just show you what opinions you believ about yourself that you do not like. Other people just help point out what you are still defining yourself as.
When you stop defining yourself and give the self-judgements of the mind less importance and belief, what others think of you will become less of a concern.
If you have no opinion of yourself, the opinion others have of you will seem quite meaningless. If you hold a strong opinion of yourself (a thought, an idea of who you are), the opinions of others will seem more threatening.
There is no need to tie yourself to something so unstable as an opinion or self-judgement
You are the stable awareness, merely witnessing all self-judgements and opinions that may arise in the mind, without belief.