"It's cheaper to keep her." Divorce Lawyer quote. LOL.
Your relationship isn't in the best situation. I would not rely on the fact that there are no more Facebook messages. He was caught on that medium and is likely using another.
If another woman is saying, "I love you" to your husband, then she either is a fruitcake or he's done something to cause her to say it. If it is a real relationship, then it will have to also die a natural death. People in extramarital relationships with "love you" words really don't want to end it, and if they did end it ....would prefer to do it after a 10 day long cruise together.
The best (ok, sharpest) advice I heard is for the wife to write BOTH her husband and the girlfriend for a 3-way dinner date at a local restaurant so all three of you can come to an understanding. The husband has usually made the wife look bad to the girlfriend. This is the wife's chance to set her reputation straight, set the rules for the post affair game, and to get a feel for if the relationship is truly over. I don't think the 3 way happens alot, but it scares the pants off the husband and girlfriend.
Perhaps a more gentler way to do it is to tell your husband to "go to the other woman, you love him so much tht you'd hate for hiim to lose the 'love of his life'"; but with the understanding that you will not wait around for him to decide. If someone else comes your way, you may not be around for him when he gets back.
I realize you are in limbo with this relationship. You are having alot of trouble deciding what to do. You seem to analyze the situation, and will make a move when you are ready. Just don't let it go on too long, becuase wallowing in a toxic relationship is not healthy for you. You will feel better when you can move on with your life.
Skeeter