Completely unhinged ADHD partner

My ADHD partner is depressed randomly all the time.

Everything will be going great then he will be randomly upset about something that happened months or years apart. It's emotionally exhausting because I always have to say sorry to make him feel better even if the argument we had (which was already resolved) was a situation that essentially was his fault. I'm considering requesting his doctor gives him antidepressants because without weed he's completely unhinged. Every day we have arguments because he's become hypersensitive about the slightest issues. I have reached the height of my emotional bandwidth.