My husband and I have been married 18 years today, we are like strangers now, how do we get back like we was ?

my husband does not sleep in the bed with me most of the time, we have sex maybe every other month, when he comes home from work, he may say ten words to me, when i ask him what is wrong, all I hear is nothing, go to his recliner and just watches tv, we don't like the same things anymore, all he wants to do is fish, camp, hunt with his brother, just like we were suppose to celebrate our anniversary this weekend and his brother calls and ask him to go hunting, he goes, and leaves me home alone, I ask him how was his hunting trip was, all he would say was fine, and that he don't feel like talking, I hear that all the time, he used to call me from work at least 2 to 3 times aweek to tell me loves me, or to invite me to lunch, he does not do that anymore, I use to be able to stop at his office anytime, now I have to call him, before I come over, I feel like we are just roomates, I don't know how to get us back where we were, he just don't seem to care about us anymore, I am at the point of just leaving.