You cannot protect him from life forever. Things happen in life, death, loss of jobs, season changes. All can be triggers for an addict, but they will continue to happen.
I too would simply have normal conversation and that is it. You never have to defend yourself. If he asks for something, simply say no. If he asks you to defend yourself, simply say you don't feel like you have to defend your choices to him.
You are walking on eggshells, it's no wonder you feel the way you do. My heart goes out to you. Sending you a hug.