Explaining Anxiety?

So I have a bf and god I love him to death, but when I get anxiety attacks or I start thinking like a crazy person and then get upset, it's hard for me to explain I have a mentally complex mind and I've tried so hard to explain to him that it's just my mind set and I try to overcome that and like he says, think more positive, but when I do it lasts about a good 2-3 days if not a week and then I'm back where I started. I've given him articles to read and videos and I mean he tries to understand but he doesn't and it's frustrating and idk what more to do. Does anyone have any advice? It'd be greatly appreciated!