The bitter friend with the "holier-than-thou" complex.

To those who have given me advice on my last question, I thank you. I ignored my friend (G) for a long while, and didn't start talking to him until he started texting me about normal stuff. He even started sitting next to me on the bus and waving to me every chance he got, something that rarely happened before I started ignoring him. But then for two days straight he stopped sitting next to me and would duck his head and look away every time I would wave or say hi. Out of habit for feeling concerned, I asked him what was wrong. He then went on his usual tirade, talking about how the whole world and everyone in it is sh*t. Again I argued with him, because I guess I'm just as stubborn as him. We got into one of our worst fights, and, to quote he said "I hate this world and all the people in it I am so tired of being criticized and told I am wrong even from those I believed my friends. The world is sh*t."
One of our mutual friends then asked if we got into these arguements often, to which (G) said that yes, we did, and that knowing me I wouldn't be giving up until he pretended to be happy and my friend with a smile on his face. For some reason, that took it too far for me, as if he was pretending to like me or pretending to be my friend. I blew up on him, not quite sure what I said, and stormed away.
I don't intend to talk to him again. Although the empathetic side of me really wants to apologize and somehow find a way to help, I've had enough and can't take much more for my sanity. This isn't really a question, I just wanted to update and was curious about your thoughts on this. Thanks for reading.