Am I the problem? Therapist says so?

My husband and I recently started marriage counseling after a huge fight where he blew up at me and called me names after I kept bugging him when he asked to be left alone. Therapist said I didn't respect his boundaries and the verbal outlast wouldn't have happened if I respected his boundaries.

We had a road rage scare awhile ago where my husband had our kids in the car and the driver pulled a gun. My husband grew up in a house full of racism and cut them off as he got older and realized it was wrong. My husband our entire marriage has never said anything racist but once that guy pulled a gun he went off in a panic and in his flurry of "idiot, maniac, etc" he said a racist generalization.

Our therapist says I have said things I regret and don't mean and shouldn't hold it over his head as we've been together many years and it has happened once and in a not normal life or death situation. She said people grow up in racist houses and in his panicked state of mind he said something he shouldn't have and that I am the problem for repeatedly bringing it up after he apologized. She said it's not fair for me to make him swear not to say anything offensive again as all he can do is try his best, and he promised to try his best and that he learned and is not that type of person.

Our therapist said I am causing most of our unhappiness as I'm the one badgering him when he wants to be left alone so therefore I cause the arguing, and that I cause the issues by repeatedly bringing up his one mistake and defining him by it when I should realize he's human and all of us say things we don't mean and regret later.

Am I the issue?