Why you checked DNA? There must be sth happened triggering you to do this. I think the first thing to do is to handle your relationship with your partner/wife. I don't know what happened so it's difficult to say anything. Take care and bear in mind, bb knows nothing and has done nothing wrong.
I know you must feel very 'heavy' and painful. I understand. Dunno what to say to make you feel better cos life is full of unexpected things and sometimes we have to face difficult issues. You must get over it. Hope you can keep a peaceful mind.
Will pray for you! God never promised us an easy journey life but only a safe arrival.