I am so sorry this has happened to you but I sense that you are strong and maybe not as surprised by your husband's behavior as hurt by what has happened.
Do you really want to let your son go with this man that has no relationship with his Father, Just food for thought?
Were you happy in the relationship? Sit back for a moment and think to yourself 'Was I happy in my relationship?' If you were not happy then you need to ask another question. Ask yourself 'Can I foresee myself ever being happy in this relationship?'
The decision to divorce is never easy, but you do have options. You need to be able to look at your life as whole and decide if it is good or bad. You also need to look at every possible aspect of your relationship with your spouse and see if the good outweighs the bad, or if the bad outweighs the good. Sometimes your judgment is clouded when you only focus on the good or only on the bad. The bottom line is to do what you need to do to have a more fulfilling and happy life.
You gave up a lot by relocating and opening up your heart with forgiveness. Now perhaps it is in your best interest to move back to where you were happy while he was gone.
Remember you can only change yourself not another person.
I am feeling very concerned for you. Tonight, watch some television, read a book, call an old friend...............eat some chocolate.
Don't sit alone and cry, instead celebrate all your accomplishments knowing you will move on and life will be better.