My Betta died :(

I got my first Betta fish for Christmas. I put it by my bed with a light shining into the tank. I'm not sure how he died. He did have ICH i'm pretty sure. could he have died from that? and in his last couple days he kept running into the wall fighting itself. I want to get another one but i don't want to kill it too. How do you think it died? Oh and my fish was so weird, it literally lay on the bottom on the tank in the rocks or like bury itself and make like a nest. I don't know if this was normal or not, i feel like he was retarded. haha