You are in the right place here. Most of us have been exactly where you are, so welcome.
If you want your husband to return, you need to draw him back to you. Sending him love notes is you pursuing him. So stop with the notes and phone calls and emails. I know it sounds strange, but you need to back off big time. Stop chasing him. And stop concerning yourself with what he is doing. You cannot control it, so don't worry about it. Concern yourself with yourself.
Have you read Michelle's book Divorce Remedy ? If not, buy it ASAP, but don't let your husband know that you bought the book or that you visit this website. You need to operate under the cover of darkness here. The less he knows, the better. Once you have the book, turn to page 124 and read the section titled Last Resort Technique. Read it twice... then do it. Next, read the rest of the book.
You need to do stuff outside the marriage (get a life). Join a mother's club, health club, exercise group, adult education class, etc. It is important that you occupy your mind, and at the same time, show your husband that you will be OK without him.
Divorce Busting is not really about saving marriages as much as it is about saving people. You will be OK whether or not your marriage survives. You need to focus less on your husband and more on you. You need to work on yourself from the inside out.
Visit this website, poke around, read about how others are coping. Share. Learn.
Finally, and most importantly, you need to convince yourself of this reality: Your happiness is not dependent on the love and acceptance of your husband. Your happiness is in your hands, and you need to believe it and live it.
In spite of my insomnia, I am very tired, so I need to wrap this up. But I am sure that others will be adding to what I have written. And I invite you to add any detail that will allow us to help you more.