I will pray for you, but I do want to share you the story of my sister, this is all still in progress and very new, so I can't give you the ultimate outcome.
Over the past several years, my sister and her husband have been growing apart from eachother, and from the church. My sister had been sensing increasing distance especially over the last few months, and about a month ago, having nothing left inside her, she laid down before God and prayed for His guidance and help to save their marriage.
The very next day, her friend called her and said "hey I just saw this moving Fireproof, you should see it!". So she did, and went out that night and bought the love dare. The next day she started the love dare, that same day her husband told her he had been having an affair for 6 months and wished for a divorce.
Committed to her promise to God when they were married, her desire to live a life of Jesus and forgive, and her love for her family, she instead decided to fight for her marriage and plow through with the love dare. Last I knew she was on around Day 25, and the change in her is immense. Not only that, but I have had the pleasure of talking to her husband over the last week or so, over nothing in particular (certainly not about their problems) and the tone in his voice was simply amazing. My brother in law has never been particularly nice to me, and conversations usually feel forced and uncomfortable. This conversation in particular was upbeat, comfortable, and normal.
You came to a Christian site asking for Christian help. My advice to you is to lay down before our Savior and ask for His help. Remember that you promised God that you would see this marriage through good times and bad.
I write this not with the intention of being condescending or judgmental, I write it out of love and hope that you can salvage the gift that God gave you.