My girlfriend always says that this is not good for me and that is not right.

Maybe you are not what he wants you to be in many ways, so he will say that you are not good here and wrong there, and he will think that you have many shortcomings. You can change yourself. Don't be so likely that you are not what he wants you to be in many ways, so he will say that you are not good here or wrong there, and he will think that you have many shortcomings. You can change yourself, don't always let him talk about you.