Humanly speaking, there may not seem to be much hope–but there always is with God. Jesus once said, "What is impossible with men is possible with God" (Luke 18:27).
Perhaps you've heard people say, "When all else fails, then pray." In one way, it's not very sound advice; we ought to pray first, not after we've tried everything else! But it still came to mind when I read your letter, because even when no other avenue seems open to us, God has still given us the privilege of prayer. The Bible says, "This is the confidence we have in approaching God: that if we ask anything according to his will, he hears us" (1 John 5:14).
Does this mean if you pray enough God will definitely restore your marriage? I wish I could promise that–but to be honest, I can't. Your wife has apparently turned her back on God and allowed herself to become entangled by Satan's lies, and his hold on her may be very strong. But I pray not.
In the meantime, keep praying, and do whatever you can to let your wife know of your love. If you also were at fault in some way, confess it to God and seek His forgiveness–as well as your wife's. Most of all, trust Christ for your future, and keep trusting Him no matter what happens.