Numb is just what would be expected at this point. That will go away and a whole range of emotions will follow. Rage, sorry, and pain that is unbearable.
Everything depends on your husband and how he handles this. If he wants to keep you then it will be on him to step up.
There are many, many, articles in the healing library on this site and there are great books to guide you along.
Right now, just know that you do not have to decide anything. Try to protect your health. It is hard to sleep, eat, or do anything else when you are in these first stages of shock and disbelief.
Just remember, this is not necessarilly the end of your marriage. You can get through this.
Just keep posting here. You will get understanding, love, and support.