Its weird, however i seem to keep a square clubface on my backswing, but my swing plane is across the line. Please help with a drill to overcome closing the face on the halfway back, or some advice please!!!

When i first played, i never had this problem, where the clubface would either open or close during the swing, causing inconcistency in my ballstriking, and my golf grip in my left hand. What can i do about too much opening/closing of the clubface..