Halfway. It may not feel like it all of the time and you may still be wondering how am I ever going to forgive or other troubling thoughts, but you are doing great. It takes a lot of courage to get to this place.
This 5th rest stop is significant. Remember, my friend Gary told me that to bike 100 miles in the MS150 I didn't need to think about going the entire 100 miles. I just had to do 10 miles 10 times because every ten miles there was a rest stop with food and drink to regain strength and to rest a bit for the next leg.
So here we are at the 5th one which is lunch! Take a full meal because you are halfway home. If you turn around and look back you can see you have made significant progress. Fifty miles means you have been through a plethora of experiences. You've sped down some hills, took in some beautiful sights, had some near wrecks, the rain pelted your face like tiny little stabs, your legs burned churning up hills and you dodged some stuff on the road that others tossed your way.
And now you have a plate full of lunch. Look around. There are so many others in a similar position to you and your spouse. It can feel like you are the only ones, but that is a lie from the enemy. Give the enemy his due. He can get us distracted and believing lies that cause us to risk what is most valuable for a mirage. Going back to the Garden of Eden he is able to persuade us to minimize and mistrust that which is truly most important. He uses our good desires such as; longing for significance, acceptance and/or affirmation to cause pain to those we love the most.
Look around. You aren't the only one who has fallen for his lies. Affairs don't solve the problems that lead to them. The people sitting around you have been humbled. Their lives have been flipped upside down but they have worked hard like you. They are just plopped down on the ground not caring if they have a fancy chair and table to eat from. They are literally earthy. Eugene Peterson said that King David had an earthy spirituality and healing from infidelity knocks us to our knees and puts our butts on the dirt and helps us to learn more of what earthy means.
You're a little sweaty and a little dirty but so what. Your heart is much more important than your outward disheveledness.
Look up. Your hope is building because you continue to make progress. That doesn't mean all doubts have been eliminated, but it does mean you are committed to continue pedaling. 50 miles to go. Make that 10 miles 5 times.