I want my fiancees mom to accept me, since we're getting married, how should I go about this?

The only people that matter now is you and Jessica, You have tried your best, what more is there? It would be nice to have her blessing but if you don't get it are you going to change your mind about getting married No! So concentrate on your marriage and be happy. Best of everything, and I truly hope that some day she will accept you.