Perhaps if you give your wife some additional attention she may come around? Also, have your lover and wife met? Do you think they could be friends? Maybe if the two of them forge a bond or friendship this may put your wives' mind at ease. I know it seems strange - but I am in your wives situation now and only trying to perhaps give you some insight into how she may be feeling.
Good Luck to the 3 of you. I hope that you can find balance with your wife and lover.