How do i fully explain this to my partner?

I have self dignosed OSDD 1b. And i had a new person form today and they were hella confused and saying things that just weren't true about me. And my partner knows i have OSDD but hasnt rly 'seen' it ig, because i have been doing so well with my mental health. Well life said fuck that and i am struggling again, Pretty sure new person formed, currently Aron the gatekeeper. Anyways, how do i fully explain this, in a way a singlet can understand and still be able to help to some extent. I know they wont rly ever understand but how can i help explain?