relationship with someone you love with stage 4nsclc

I am thinking about going to support group. My boyfriend has stage 4 nsclc and he doesn't do anything we used to anymore. He changed many ways. One is he doesn't want to take walks no more. Other is he used to hang in his room a lot and doesn't do that. Sometimes I want to do my own things and he doesn't want me too. He doesn't cuddle with me anymore unless I ask for it. Also he never watched reality tv and now he does with his mom. He wants to be around his mom more and me a lot less. But does want me hanging out with the both of them. I want time with just him at times. They say I am over reacting but he wants to marry me and I wonder why he doesn't want to be around me really anymore and would prefer to be with his mom. One day I left for the whole day so he could spend it with his mom. When I returned he said he missed me and spent a hour with me when his mom was gone. After she returned he was back with her and I went to the room. Thinking if he really missed me he would come to the room. When I text him he said he was watching a show (which is reality and hates when I watch it). Why do I feel like he is pushing me away?