I don’t know what going on, I really needs help to clear my brain

Me and my boyfriend been together year and a half. In the beginning he was happy to spent time with me, and having sex.

Now, since December, we have sex if I am gonna ask him, and sometimes he refused me, and he pretend he is tired, stress out from his job, money and stuff like that. I am working and I am totally independent, I never asked him for something, or money. We can see each other just in the weekend because we both are working. But if I am not going there, he never asked me to go . I really love him but something is not right. He looks like he is looking for sister to spent time home, no for the girlfriend