Where did the spark go?😢

Hey guys! So me and my boyfriend have been together for about 3 1/2 years now and I remembered when I used to be on my period he would take care of me, but me my favorite snacks and be so loving. Now he's the total opposite. He doesn't do anything sweet like that. When my backs hurt really bad he doesn't want to rub it or when I want to cuddle with him he does want me on him. He gets upset when I cry about the pain cause there's nothing I can do about it and have to deal with it. I know in my relationship I can be a bitch but if I'm being so loving (which I'm usually not when I'm on my period) why is he so rude? I just miss all the sweet things. What should I do??😭