Move back into your bed. Immediately. Why are you sleeping on the couch???
See a good "men's rights" attorney. Immediately.
If it (helping her) helps the joint family income, then MAYBE, but I wouldn't be doing anything else "husbandish," as she has fired you as her husband. It's pursuing and enabling when you help her.
Stay dim, conversing only about the kids. When you DO find yourself around her, be courteous. Treat her like a roommate who's a friend.
You need to protect -- firewall -- your finances IMMEDIATELY. Once she thinks you're serious about cutting her off, people can do desperate things when they're being fueled by the strong pull of ENTITLEMENT that is an affair.
