You have a lot of prayers here. I would highly recommend seeking a priest out on this.
Next, even if you would have divorced before becoming Catholic, if you were both baptised christian protestants and were married in a Christian church, your marriage may well still be valid.
An annulment looks at essential elements at the time the marriage took place.
I was in an invalid marriage at one time.
If you are in an abusive marriage as you speak of I would recommend separation, not divorce.
Again, I highly recommend swallowing what pride, guilt, fear you may have and see your priest, schedule some private time with him. It may do a world of good.