Triggers and Landmines

Living with someone who has PTSD is kinda like living in a field of landmines. Most of the time, life goes on, like normal. That's when you're walking around the outer perimeters of the landmines. You know they are there, but everything's going okay. Then something happens, you trip into the mines and there's an explosion. That's when he has an "episode". 
My husband's episodes usually consist of him getting angry (or feeling rage) over something. Sometimes, it consists of what I call "shut-down mode".  He pretty much shuts down and just goes through the motions of whatever he's doing. There's no talking, no emotions. No interaction what so ever.
And from my side, I never really know what it is that triggers them. So, that of course puts me into cautious mode. I don't want to make it worse or trigger something again. So, I walk on tip-toes avoiding the landmines. Which I think is a trigger all in itself.  The fact that I'm tip-toeing around. But what else do I do?
I don't know how to react to this.
Especially when it happens in public, I just want to cry. I don't know what to do. I don't know what's going to happen. So, I just hurry and do what we are out for and go so we can get back home. At least at home, we can go separate ways until everything has de-escalated and gone back to normal.  Is this how life is going to be now? How do we deal with this? 
How do I be supportive without being too motherly or overbearing?
And how do I show my emotions without them triggering an episode? Should I pretend I have none as well?

How do we learn to live with this?