How can some guys went cold from affectionate in just one single day?? Can feelings change that quick ?

It has happened to me twice when a guy I’m seeing was super affectionate and we had a really good time together and he calls me and texts me every day. Suddenly one day they stops calling me or texting me. The first guy just completed shut me out and this guy is doing it slowly. When I call him he acts normal but I can tell things are different. I have a feeling that he’s getting distant gradually but how did they change their mind so quickly?? I mean yesterday we were cuddling and kissing – do guys cuddle and kiss someone they don’t like ? Did he hang out with me just to kill time? I just don’t understand. When I first met him , he really liked me (at least it seems so) but couple months after he doesn’t want me anymore. It has happened to me two times already and I’m starting to worry if there’s something wrong with me : (

Omg being unwanted sucks.

I could just forget about this guy and move on but we have been seeing each other for more than three months and I think I need to talk to him about this in person. I know no one owns me anything and he doesn’t have the obligation to explain to me. But I can’t be tossed away like trash. If he respects me, he should at least tell me he’s not interested anymore rather than simply acting cold, right ? Sorry about the rant : ( This just makes me so sad.