Is dicorce haram? / is this reason to divorce halal?

I know that there are good reasons for getting divorced, but my husband and I have almost been married for 6 months and all of a sudden he is saying he doesn't want me any more and he wasn't ready to be married because he wants to party and live the single life. I don't understand where all of this came from. But he stopped praying and reading quran, and he quit his job, and now he is going out and partying and inviting girls with him he took one girl on a date to a nice Italian restaurant. I just don't understand because I give him whatever he asks of me, and I never even speak to guys. What should I do? And is it haram to divorce under these pretences?