If your man goes from hot to cold, from doting to casual disrespect or from excitement over you to ambivalence, he may have had a change of heart about your coupling. Be sure to examine the total picture; family, money and health woes can cause someone to behave out of character as well. If he says there isn’t anything disturbing going on in his life, yet he has a 180-degree change when it comes to how he treats you, then it is very likely that the end of the road is near. You could possibly have grown apart–it happens. But ask questions. Don’t be afraid to confront him about his behavior. And be clear: switching up how he deals with you may be a cowardly way of attempting to get you to break up with him instead of doing the dirty work himself.
If you attempt to get answers about his new attitude and are met with a brick wall or a “nothing has changed” commentary, continue to look at the signs. If he no longer wants to spend time together, is unfriendly when he does see you, no longer wants to make love (or, perhaps the only time he wants to see you is in bed) and/or he talks to you out the side of his neck however, then you have to let him know in no uncertain terms that you will not put up with such disrespectful treatment and that if he no longer wants to be together, then he should simply say so.
You can let him know if you were happy with the relationship prior to his attitude shift and are willing to try and make things work, but you can’t enter this conversation from a place of begging or pleading. Simply put it out there: “I’d like to stay together and work on what we have, but if that is no longer something you want, I just want for you to tell me. I can handle that. But I can’t handle being treated badly.” If it’s walking papers he wants, then serve them. If his heart isn’t with you anymore, you are doing yourself a disservice by attempting to hold on.