I'm going to ignore my friend after he called my housemate because he (mistakenly) believed I was very depressed
What is your reason for wanting to simply ignore the guy?
I don't think it's a good idea to have a friendship with him anymore.
I think that you need to tell him that then. Just ignoring him is so much more hurtful.
Nah, he will just get pissed at me and I don't know what he will say in reply. And then people will tell me to be nice to him.
It is a really bad habit to get into ignoring your friends. It feels awful to be ignored, so try to imagine how your friend would feel if you did this to them. Also, it is not helping the situation at all to simply ignore it and not talk about it.