Hi RM,
I am so thankful that you have been released from the bondage to this sin. That is certainly something to be praising God about!
My advice for now, while your husband is abroad, is to PRAY for him everyday. Pray for his chastity, for his conversion of heart and mind in this matter, and for your marriage. Be loving and respectful if he brings it up, but definitely stand your ground on it. He will not benefit if you consent to sin with him. Be careful not to make him feel ashamed. Just plainly say that you understand now that it is wrong, and that while you are longing to be reunited with him again, you want to do what is right. Acknowledge that it is a huge sacrifice to be apart and it is a tremendous struggle to remain chaste. It is important for you and him to be united and for him to understand that you understand his suffering, being away from you and away from home. He may or may not fall into solo masturbation. Pray now, that if the situation arises where he wants to talk about it, that the Holy Spirit will guide you in your reaction and response.
I think that, generally speaking, it takes a while for one spouse to “catch up” when their spouse has gone through such a big conversion as you have. It will be challenging for you to remain patient and compassionate when it is all so clear to you now. But your loving witness can be a source of sanctification for your husband now. I have seen similar transformation in my own marriage and have heard testimonies of similar experiences in other marriages. God bless!