I'm scared to take a break

I've been with my boyfriend for well over a year now and even though I'm happy and that I love him, I feel like I need a break. Not necessarily because of him, but because of me. I don't feel myself anymore. I don't enjoy spending time with my friends or family. Sometimes even my boyfriend like I used to. I don't laugh hard as much as I used to. I'm not as excited anymore. I've been really moody lately and I'm tired of it. I just want to focus on me for a little bit. Maybe even a week. Try to quit social media as much as I can. Being on my phone in general. But I think the only thing I can really think of to why I am also not feeling as great in my relationship is because I deal with anxiety and depression. My boyfriend doesn't seem to understand and want to really understand. From his own expierence, he said he had all his mood swings on purpose to get attention. So he says he doesn't know what to say when I asked if he thinks I do it for attention. Which I really don't. Obviously what he was going through, wasn't as serious and real. Mine is. He is still there to comfort me and hold me when I'm feeling low, but I don't feel as comfortable because he wont fully believe me. That's the only thing that really bugs me in our relationship. Yeah I get it that not everyone can fully understand. And I get that he's still trying in some way. I still love him fully and he still makes me happy. I just want that to change. It sorta feels like it's holding me back. But I also have the power to change myself without others. But that doesn't mean I don't want the help. Besides that part, I just feel kind of empty and have been for almost 3 weeks. I'm tired of it. But I'm afraid to ask for a break because what if I start to feel better and then he doesn't want me back? What if he doesn't understand what a break is and what it's used for? Any advice on how to talk to him about it?