Leave, stay, what??

So the last several months me and my SO only have sex 1-2 times a month. So ttc is really not on the table anymore. I don't know if he's not attracted to me anymore or cheating on me. I could only really think of the things of why. Why isn't he having sex with me. Why? Why? But we take showers together and everything's fine then we get in bed and he turns over and falls asleep. No I love you, no good night.... nothing. What do y'all think? I'm way fed up. Leave him? Move out for awhile? What??? I'm almost done. Seems like he's never there for me anymore. Kinda sucks and saddens me. Help?