i used to have a similar problem of a horrible open face push-slice.

*i fixed it by strengthening grip a bit,

*but the main thing was ( i know this sounds wierd) but sometimes my right hand will take over and hold the face open so i used a 2 and sometimes 3 finger overlap (one finger on the club really) and that helped me to have less of a right hand role. then do back to your old grip.

*also remember having a very loose grip and arms. to much tension can prevent you from releasing the club. almost feel that your grip is so loose that the club feels almost heavy and hard to bring to the top.

you need good grips on your club, tension is a swing killer! hold the club in your fingers and not the palms.