I think you are being much too hard on yourself. I bet many people get results that indicate they view mental illness as a weakness. We all internalize the biases of whatever culture we live in, and mental illness is stigmatized throughout the world. So while you know that prejudice against mental illness is wrong on a rational level, it is possible you subconsciously harbor negative feelings about it, particularly if you have shame over your own mental health struggles. What matters is how you act, and you indicate that you behave in ways that seek to lessen the stigma surrounding mental illness.