Just wanted to offer hugs and reassurance. You'll get through this. I think it will take some time before you actually *feel* brave but you are *acting* brave already.
And the thing about whether or not a fear is a phantom fear or a response to an actual threat? That's a hard one to answer. Forgive me for sounding platitudinous, but if you feel fear, it's real to you, and you deserve to feel safe. So if there are things you can put in place (like having a friend nearby whenever you must encounter STBX, or even having a cell phone in your hand with 911 on speed-dial), go ahead and do them. Don't worry about whether they seem silly or unneeded. It's about you and making you feel safe.