You know what you have to do and it doesn't involve being in a loveless marriage. As far as your husband people can always emotionally survive. It is painful but you aren't doing him any favors by staying together. You have to give him the benefit of the doubt. People move on from long relationships all the time. You can't stay out of guilt. As far as finances that can be resolved with a lawyer. I think it feels terrible to look at what will happen but you have no other choice. The alternative is to stay together knowing you will never be happy. You are operating right now out of guilt but that can't be the basis of your love life. He will handle this in his own way. I think you should do him a favor and be honest. Every day you are not you really are living a lie and that benefits no one.
If this has been helpful press accept