You have always stood up for yourself. I do not mean that you always did the best you could, because that cliché ignores the fact of our poor decisions, our fearful reaction, our way too angry response, or our drunken folly. We could do better. We are not always sharp. But you have always stood up for yourself, in many different ways. Sometimes with silence accompanied by a dirty look and the inner contempt towards the idiot who just hurt you. Sometimes with a shout or a bit of subtle or overt revenge. Sometimes with going along outwardly because the other had the power-and you had to wait for your turn. Sometimes with a fantasy of murder or the infliction of injury.
You get the point.
You are more experienced at standing up for yourself than you perhaps realized.
There’s hope.