How do I tell a friend I'm still pissed at him without starting a fight?

not_a_twinkie
So my friend and I were having a conversation a few weeks back when he suddenly blew up at me calling me an egotistical cunt with no real friends, a liar, a bitch, and a coward, to summarise. Then told me not to speak to him again.
I ended up talking to a mutual friend because I was understandably upset and confused and wanted someone to talk to, they just told me to talk to him and sort out what had happened.
Anyway he ends up messaging me after a while with a half assed explanation and no apology then goes back to messaging as usual after a quip about me giving him the silent treatment.
I'm still kinda pissed if I'm being honest, but he wants to act like it never happened and just go back to the way we used to talk which I just can't do while still mad, however I know he can be unstable and I don't know if I can bring it up without causing a fight.
How do I tell a friend I'm still pissed at him without starting a fight?
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