I have a problem...

My best friend and I hav known each other ever since I got him out of that piece of shit foster home, and I've never known him to act like this about anything. He just started screaming and freaking out at me and then when I asked him what's wrong, he wouldn't even look me in the eye, he just got up and left. I've tried calling him but he won't pick up. He hasn't been showing signs of being suicidal or anything... Somebody help?