If your wife is the one who does not want to stay in the marriage why in the world do you feel like you have to be the one to move out. If she is that unhappy, and you have not physically or emotionally abused her, you have not been unfaithful to her, then she, not you, should be the one to suffer the consequences of moving out of the family home - without the children.
Like Sandi said above, it's tough love time for the 23 year old. Time for him to stand on his feet, take ownership of his problems and deal with them in a positive way. In a sense you are enabling his behaviour and keeping him from kicking his habits by allowing him to "bring his anger home to you".
Finally, I suspect you already know that your wife is involved with someone else, either an EA or PA. This is why you are asking her who is texting her and answering her emails. It is extremely suspicious for someone who begins to connect with old friends on FB to follow that up with unhappiness in the marriage and wanting a separation for a year.
Read the books and put the recommendations Michelle makes into action. You have a long road ahead, but you can do this!
