Advice?

So my bf and I make 2 years (officially) next week... for some reason this year hasn’t been our year AT ALL. We’ve gotten better but every single time we get into it, he says he’s leaving me and sometimes even disappears for days 😩 . Does this mean he doesn’t wanna be with me?? I’m so tired of it but I don’t wanna throw away 3 years. What should I do?