Dealing with Ableism from My Dentist

So I am frustrated because my dentist has been acting somewhat ableist. I have always had a hard time with getting into routine brushing my teeth, really I am trying my hardest but I always either forget or I just don’t have the mental or physical energy for it. I told him it’s hard due to executive dysfunction and he just kind of brushed it off like I was *trying* to make things more difficult. I explained I’m aiming for once a day right now (as it’s a more reasonable goal for me at the moment) and he starts yelling at me about how I need to start doing it twice a day or I’m wasting all of this money on the dental work, and I get where he’s coming from but I just wish he understood. He’s from a different culture and I don’t think he takes mental disorders as seriously as he should, as a healthcare provider. It just makes me feel like garbage and frustrates me as well, and he’s good at dentistry and all but I just wish he was more open minded. I don’t have the time or energy rn to find a whole new dentist, so does anyone have any suggestions of good ways to cope with this or better ways to communicate with him? Also any tips for getting myself into a routine of teeth brushing would be nice as well, as reminders don’t work for me cause I usually just ignore them. I just feel I’ve tried so much at this point and I’m sick of being treated like this for my struggles.