Been dating a guy 4 mos. Mon. night he sd. he's so in love w/ me...have hardly heard from him since.

We have been friends since we were kids and this is our second time dating. He calls me and texts me all throughout the day and has been for the full 4 months. Monday night he opened up and we had a great convo. He said he loves me with everything in him and always will and wants me in his life forever. He said he wished he'd never let me go the first time and was a fool to let me go back then. I felt so connected to him and we talked for hours. Since then, he has been distant and less playful. Today I have not heard from him at all. What happened?