My partner thinks im taking things too literally/overreacting

Hello everyone, this is my first post on here

I (27NB/amab) was diagnosed with autism a bit more than a year ago and ive been with my partner (26M/NT but maybe ADHD) for a bit more than 4years.

For context: we live in western europe where there have been multiple heatwaves since the end of May and its been really hard for me to cope with it (ecoanxiety at an all time high+sensory issues through the roof). Ive had multiple discussions with my partner about how hopeless it made me feel and how sometimes it made me consider living/leaving this life. He always tries to reassure me which is nice but i can see he feels im stuck and knows he cannot do a lot to change my mind (bc it would just mean the state of the world gets better).

Yersterday he sent me a screenshot of a reddit post of someone saying they could not handle the heat anymore/that they felt like they could not live like that knowing it would only get worse. With the image he said "you wrote this didn't you lol" (it was in french so not really that but the tone was that). I told him i didnt and that it wasnt funny anyways to which he replied "._." so i went on a tangeant telling him it was not cool to joke about people wanting to die bc of the climate crisis especially after i had told him my fears in the past.

He told me he sent me this bc he wanted to show me i was not alone, to which i said it was weird, bc i know im not the only one who wants to be out of this burning world... He doesn't understand where i come from and keeps on telling me im overreacting/he is tired that i take things too literally.

It gets in my head and now i wonder if im the bad guy/im being too sensitive even though i know its not ok for him to joke about my suicidal thoughts related to climate change.

I dont know how to say to him that some things are really important to me and that i feel he doesn't listen to me or register the info i give him. Have you ever been in a similar situation?