My husband and I has become a stranger?

We've just been married for 3 years , we had a boy (18 months) . Lately I always feel that he doesn't love me anymore . When he came back from working , he always looking for my boy , not me . When he saw me , he hardly have something to say to me . We do not have any romantic life , even when we are having , at first we had a 3 times a week , but now hardly have once in a month . When I asked abt it , he said " oh pls , I'm so tired " . But he still have the energy to play badminton . What should I do now ? Should I have a divorce ?