Let go of your constant strife to sustain and assert the idea of who you should be, your obsessions about what you must accomplish in your life.
It is this massive effort of defining this bogus identity that keeps you wedged in the chronic routine of comparisons and conflicts with whoever and whatever appears to threaten this idea.
If you have tried to assert yourself for many years, following any advice on the topic, desperate to get some self-esteem, and you have accomplished nothing, then be honest and do something different. Stop it and just accept that you are nothing.
Try it for one day. Release your idea of being someone or something, and just be nothing, be the void.
And as you keep accomplishing nothing, fully accepting that you are nothing, you may realise that you can both accomplish and be all that is.