Well. The good news is that explains his wild mood swings and his irrational anger at you.
But that doesn't make things any easier for you, and it's ok to be scared.
I assume you snooped at cell phone records? I know some will slap you for snooping but, um, I say ignorance is bliss but knowledge is power. How you use the knowledge is the important part.
Oh, and ((((((((((1hope)))))))))))
Do you have absolute proof it is a woman? without a doubt there is no reason for contact other than an EA?
If so, what do YOU want to do?
Live your life while you are still living. Riding the trail less traveled.