I just wanted to welcome you to our forum.
Sorry things have gone so badly so far. It sounds like your wife is really rushing into this, and not considering your feelings. You both have damage from being cheated on in the past; you need to take this poly thing very slowly.
"Saying she needed him to treat her badly so she could get over these feelings, and that she has never loved anyone like him (killed me when she told me that)."
Ow; I think it would hurt anyone to hear something like that.
Things are really strange with your wife right now; you could use some couple's counseling if she'd agree to it.
Try to take care of you during this difficult time.