SOS!!!!!

Okay so my fiancé was acting different today. He seemed really sad and upset and he wouldn't tell me wats wrong whenever I asked him. So we were texting and everything seemed okay until he wouldn't text me at all. I got worried but I didn't blow up his phone. After about a half hour I texted him asking if he was okay and he texted back that he just doesn't care about anything anymore and stopped texting. Idk how to take that comment so please help.