Meltdown help for relationships

Hi everyone I’m new here, and I was diagnosed audhd last year. I’ve been with my partner who is also audhd for 9 years but I’m struggling with meltdowns in my relationship. I have always had them through my life and they have always been physical with lashing out or inward on myself too throwing things or excessive crying if they go beyond a certain stage. I try to give verbal warning as soon as I can tell I’m going to meltdown but my partner is my biggest trigger and he doesn’t listen when I say that I’ve reached my limit which means i have a meltdown any time I feel the conflict rising. Afterwards when we are both calm we try to discuss it but he accuses me of being manipulative and having a meltdown to get my own way which feels really hurtful as I’m just trying to cope and I wish I had strategies to help, and also he is autistic but shows it in different ways to me so isn’t able to empathise. I’m not looking for advice such as “leave the relationship” as we are going to therapy in the new year both together and separately but more for any help for before I get to the stage of a physical meltdown, as I’m still really trying to navigate all of this and I’m in a major autism burnout (been diagnosed with M.E). Thanks in advance