It's OK to be human, and have valid fears.
Remember, courage is not the absence of fears, but rather enduring them and moving forward DESPITE them.
In the moment that mattered, after he beat you up, you had clarity and did the right thing. Of course somebody violating your space and violently injuring your person in front of your children is upsetting. You are understandably post-traumatic right now; this is not surprising but to be expected.
I hope you can get some face to face support in a domestic violence support group.
I am so sad that you have to endure these soul-crushing circumstances and fears.
Sending gentle support hugs and a virtual soft furry quiet room where you can go to rest.
CLMI